Follett, James - Earthsearch 03 - Deathship (v1.0) Jacked.

    THE EARTHSEARCH SAGA.
***
     BOOK TWO: CONTENTS.
     Prologue: Four Million Years Ago.
     Part One: Return.
     Part Two: Flood.
     Part Three: Surrender.
     Part Four: Solaria.
     Part Five: Sundeath.
     Part Six: Supermass.
     Part Seven: Deathship.
     Part Eight: Megalomania.
     Part Nine: Earth.
     Part Ten: Earthvoice.
***
     Book Two EARTHSEARCH -- DEATHSHIP. 

     Prologue.

      Four million years ago. . .
     Nothing stirred in the mighty ship as it swung sunwards across the solar system -- its titanic bulk eclipsing the background myriads of stars of the galaxy. Four million years would pass before Mankind gave the galaxy a name, the Milky Way, but for the time-being the celestial wheel of crowded incandescent suns was merely a number in the ship's vast and silent library.
     The passing hours and the increasing strength of the sun burning on its flawless black skin brought about a gradual awakening throughout the ship: signals flowed along hair-like fibre optic tracks, and artificial gravity was created throughout the ship's seven-mile length. It was extremely weak gravity at a level that would have ill-suited humans with their poor co- ordination and reflexes. But the intelligences aboard the starship were not men and women -- they were robots for whom the low gravity was ideal -- providing them with the necessary stability that enabled them to move with precision and purpose along the ship's scores of miles of darkened, silent corridors.
     The first such machines in the awakening were service units whose limited intelligences were adequate for straightforward tasks that required little exercise of judgement. Obeying the programs provided when they had been built, they checked all the ship's millions of miles of fibre optic circuits and carried out repairs where necessary. Satisfied that all was well, they swarmed through service hatches onto the ship's hull and subjected it to a meticulous scrutiny. But the ship's outer skin was relatively new in terms of cosmic time and therefore required little attention.
     Only when the preliminary checks were complete did the master intelligence that commanded the ship's main control room show signs of life.
     Kraken's awakening began with the absorption of oxygen by his organic brain. The shutters that covered his optical sensors --his eyes -- opened. He had not been designed and built by humans but, apart from his six manipulators, he was humanoid in appearance because his makers had discovered that a human shape was the most appropriate for a sophisticated, multiple function android with a highly-advanced intelligence. There the similarity ended: he possessed no human emotions other than a crude basic instinct of utter ruthlessness and the more sophisticated ability of low cunning. Both of which had been had been considered necessary by his makers to ensure his survival. The nearest he came to human emotions was a measure of his makers' blind, driving ambition which they had reluctantly provided him with to improve his efficacy at serving their purpose.
     Physically he was larger than any human and immensely more powerful. His height was ten feet and he possessed a formidable mass of 500 pounds. Despite his bulk, the advanced design of the servo-motors buried within his massive armoured trunk was such that he could move faster than any of the secondary androids under his command. The clusters of Herculainium alloy fingers on the ends of his multi-jointed arms were capable of the delicacy of touch needed to manoeuvre the great ship, but they could, if he so desired, seize any of the control room androids and tear them to pieces.
     Although fear was a human emotion, it manifested itself in the main control room androids because they had been programmed to ensure that they came to no harm, therefore, to avoid arousing Kraken's wrath, they took special care to subject all his orders to internal verification to be certain of carrying them out correctly.
     There were seven of them in the ship's main control room, their less sophisticated brains becoming active more quickly than their master's brain so that they would be ready for his first orders.
     When Kraken opened his eyes and dispassionately surveyed the console before him, it was of no interest how long he had spent strapped and comatose in his giant swivel chair. Ten years, ten centuries, ten thousand centuries -- the passing of time was of no consequence. All that mattered to him was the condition of the ship and whether or not it was on course for its destination. His interrogation of the main control room's First Android satisfactorily answered a number of his immediate questions concerning the ship's condition.
     "And the photonic drive?" he demanded.
     The First Android did not know what condition the ship's main drive was in but knew enough about Kraken to sense that candour was decidedly risky. Its answer required careful consideration.
     "Only you have the authority to order the testing of our main drive, Kraken," the First Android replied, bracing itself for trouble. "There have been no adverse reports from the service units therefore the probability is high that its condition is in the satisfactory state it was in when it was closed down."
     Kraken digested this and reluctantly decided that the answer, although more verbose than he cared for, gave him insufficient grounds for tearing the First Android apart.
     "Destination status?" he queried.
     The First Android began to feel more confident. The first hurdle was over. "Everything is exactly as programmed before closedown, Kraken. We are on a solar orbit that will intersect the orbit of the third planet of this solar system within five thousand hours."
     Watched anxiously by the seven androids for the slightest sign of displeasure that could herald the sudden and noisy depletion of their numbers, Kraken rose to his feet and moved silently across the main control room to the navigation console. The Second Android manning the console moved hurriedly out of his way. Kraken studied the information on the visual display screens set into the console's surface for some seconds. Everything appeared to be in order.
     Kraken returned to his console and allowed the weak gravity to lower him into his chair. "Visual on third planet," he commanded.
     The First Android touched out the necessary commands. The hologram replication field hummed briefly. A blurred patch of coloured light shimmered in the field and rapidly hardened into an image of a shining blue-green planet and a smaller crater-scarred moon -both of which appeared to be suspended above Kraken's control console. The angle in relation to the sun that the ship was approaching both bodies meant that they were reproduced in the replication field as crescents of light.
     The beauty of the shining planet was wasted on Kraken. To him it was just a planet. The only thing that gave him a grudging moment of pleasure as he studied it was that it was a perfect match with the planet that his masters had instructed him to visit. He touched the controls on his desk and viewed the planet for a few seconds in the ultra violet spectrum before switching the replicator into the electromagnetic spectrum. The patterns of invisible radiation fields surrounding the planet appeared as coils of shimmering light. Their shape and intensity tallied with the data displayed on his information screen. There was no evidence of any artificially generated radio emissions but that was only to be expected. A faint outer halo of light encircling the planet caught his attention. He pointed.
     "What's that?"
     "A dispersing band of plasma radiation," the First Android answered.
     "I can see that. It should not be there, should it?"
     "No, Kraken."
     "Have you examined it?"
     The First Android wondered if it was going to be blamed for the mysterious spiral of weak radiation.
     "Yes, Kraken."
     Fortunately Kraken was too engrossed in the phenomenon to consider any form of direct action against his subordinates.
     "Findings?"
     "All the probabilities have been studied, Kraken. The highest one that correlates with the evidence is that a ship with a similar drive system to ours has visited the planet."
     "There is no such thing as another ship," Kraken stated emphatically. "This is the only ship in existence."
     The First Android remained silent. The evidence that the third planet had been visited by another ship was irrefutable but it wasn't prepared to argue the point with Kraken.
     "Give me the rest of the data," ordered Kraken.
     "The plasma's dissipation rate measurements indicate that the ship visited the planet four years ago," said the First Android. It hesitated -- sensing that the rest of the evidence might arouse the main control room commander's grave displeasure.
     "It went into an orbit around the planet?" the giant android demanded.
     "Yes, Kraken. As you can see, the plasma belts consist of a double spiral - - one possibly caused by deceleration when the ship went into orbit, and the other caused by acceleration to escape velocity when it left orbit."
     "There is no other ship," Kraken repeated, glaring at the First Android as though challenging it to an argument.
     The First Android made no reply.
     Kraken decided to carry out his own analysis of the mysterious radiation halo. He touched out the necessary controls and requested more detailed information. The results were not to his liking: not only had a starship visited the planet four and a half years' previously, but the number of orbits that the ship had made of the planet to reach escape velocity suggested that it was a ship of a greater mass than his ship.
     The columns of glowing figures on the navigation consoles reminded Kraken that there were more pressing matters to deal with. He started issuing orders.
     Thousands of selected directional thrusters set into the mighty ship's outer skin began burning. At first the collective thrust force of all the miniature darts of plasma thrust had no affect on the ship. An hour passed before the ship began to turn in relation to the sun, and it took a further four hours of careful control of the directional thrusters to complete the reorientation manoeuvre so that the ship's huge photonic drive outlets were aimed along its course.
     When the complex computations were completed, Kraken touched the controls that fired the photonic drives. A stream of incandescent gas, over fifty miles long, blazed out from the ship.
     Although the ship had been moving slowly in comparison with its maximum interstellar velocity of 90% of the speed of light, its mass was such that it was necessary to maintain the braking burn for 4000 hours to ensure that the ship would be captured by the gravitational field of the third planet.
     "Inclined equatorial orbit stabilized at a height of one planetary diameter, Kraken," the First Android reported.
     Kraken examined the infrared image of the ocean below that was displayed in the replication field. The uniqueness of the planet --that seven tenths of its surface was covered with water and that its atmosphere contained free oxygen -- was of no interest to him even though what he was looking for could not exist on the planet without oxygen and water. His instructions did not require him to search for particular chemical compounds.
     The display in front of Kraken winked through the rapidly changing longitude and latitude readings. The most important display of all, the biosphere analyzer, stated:
     WATER -- PRIMITIVE INTELLIGENT LIFE UNLIKELY.
     Kraken sat watching with that boundless patience that only machines possess. The advantage of the inclined equatorial orbit was that the ship's position was concentrated over the temperate, sub-tropical and tropical regions of the planet where life was likely to flourish. Consequently it was a relatively simple operation to subject those regions to the most searching scrutiny.
     Even so, the high angle orbit swept the ship close to the extremities of the northern pack-ice.
     NORTH POLAR ICE -- PRIMITIVE INTELLIGENT LIFE IMPOSSIBLE.
     The frozen sea yielded to tundra and then to vast, sprawling forests that smothered the terrain with a thousand shades of green.
     PRIMITIVE INTELLIGENT LIFE POSSIBLE advised the display.
     In another part of the ship secondary surveillance systems became active and flooded Kraken's domain with detailed information on the changing terrain rolling past 8,000 miles below. Some systems studied the configurations of rivers and streams, others scanned the patterns of infrared light emanating from the planet's lush vegetation. They were all searching for the same thing: the handprint on the topography that intelligent life would have made. Pointers to that evidence were the existence of straight lines. It did not matter what they were or how vague: the edge of a forest, the bank of a stream, an indistinct mark on the landscape. If it was straight, the ship would be interested.
     Kraken and two other main control room androids sat motionless and silent before the displays. Occasionally they would reach out and touch a control to provide a visual close-up when something caught their interest. The phenomenon would be assessed, dismissed, and the long, painstaking search would continue.
     Something registered on the 89th orbit when the ship was above a continental landmass in the southern hemisphere. Both Kraken and the First Android noticed it simultaneously.
     Kraken instructed all levels of the ship's surveillance systems to lock-in on the phenomenon.
     On the eastern coast of the landmass, a thousand miles south of the equator, was a quarter mile square of vegetation of an unnaturally even colour. The square was criss-crossed with what appeared to be a pattern of irrigation ditches. There seemed little doubt that it was an artificial field system. The high gain hologram close ups revealed a cluster of four small structures located in another clearing where the lush sub-tropical vegetation tried to crowd onto the beach. A humanoid lifeform was even spotted moving down the beach to where three smaller humanoids were splashing in the surf.
     The larger creature's height and general size was easily gauged from the length and width of the shadow that it threw across the sand.
     At the top of the beach, near the structures, were some enclosures which contained a number of animals. How many of the humanoid creatures lived in the tiny community was of no consequence as far as Kraken was concerned. All that mattered was that they existed and that he had found them.
     It was time to communicate with his masters for further instructions. Kraken knew little about his masters, and cared even less, but he did know that they possessed emotions. As he studied the diminutive figure walking down the beach, he correctly guessed that they would be well pleased. Part One Return
     Astra reached the edge of the surf and watched her shrieking twins in amusement for some moments while enjoying the warmth of the setting sun on her back. Morning and evenings were the only times of day when the heat of the sun was tolerable. Like the children, she was naked apart from a pair of tough plastic sandals. The twins studiously ignored her and intensified their play in an attempt to increase her feelings of guilt when she summoned them from the water.
     She felt something and looked down. Bran was piling wet sand onto her feet. She wriggled her toes and smiled down at the toddler.
     "Hallo, Bran. Why aren't you playing with Elka and Savin?"
     The boy regarded her with a pair of large eyes that Astra always found disconcertingly expressionless for a three-year-old.
     "Don't want to," he murmured, returning to his task of burying Astra's feet.
     Astra felt a movement in the sand covering her feet. She lifted one foot clear of the heap and was surprised to see an angry adult crab scuttle away and proceed to bury itself. The creature was too large to have got into the heap by accident. Bran watched it in disappointment.
     "That was naughty, Bran," Astra scolded. "It could've hurt me."
     Bran made no reply but continued to study the crab as it disappeared into the sand.
     Astra returned her attention to the twins. Elka had stopped playing and was watching Bran intently.
     "Come on you two," Astra commanded. "Time for bed."
     There was a chorus of protests from the two children.
     "Little more, mummy," pleaded Elka.
     "You've already had a little more. It'll be dark soon. Now come on or do I have to drag you out?"
     The twins realised the uselessness of further argument with their mother. They left the sea and took her outstretched hands.
     "And you, young man," said Astra, looking back at Bran as she and the twins started up the beach to the huts.
     "Mummy get me," said Bran sulkily without looking up from the new pile of wet sand he was building.
     "Mummy's busy."
     Bran stared at Astra with fathomless eyes. "Mummy get me," he repeated doggedly.
     Astra sighed. She was about to scoop Bran under her arm when she heard Darv shout at her. She looked up. He was running towards them, waving frantically. She guessed from his expression that something was wrong.
     "Sharna's started!" said Darv breathlessly.
     "Is it definite this time?"
     "Telson thinks so. He won't say -- but I think there's something wrong."
     "All right. You look after the children. Bran can sleep in our hut tonight."
     Astra left the three children in Darv's care and ran up the beach to Telson's and Sharna's hut. The first thing she saw when she opened the hide-covered door was that Sharna's baby had just been born. Sharna was lying on her side, with her knees drawn up to her chin, on the pile of furs that served as a bed. She was moaning softly and clinging to Telson while he comforted her and tried to wipe the sweat from her body.
     He looked up at Astra in relief when she entered the hut.
     "Thank God," he said hoarsely. "I think it's due any minute now."
     Astra made no reply but knelt down and carefully picked up the newborn baby boy. The infant was holding his arms up to his neck and was clenching the umbilical cord in his tiny fingers. Telson's eyes widened in shock when he saw the child.
     "I had no idea," he whispered.
     "Surely Sharna knew?" asked Astra, quickly disengaging the baby's fingers from the cord.
     "I gave her some morphon an hour ago to help her sleep. I didn't know. . ." said Telson. He hesitated. "Is. . . Is it all right?"
     As Astra handled the baby, so was immediately aware of a lifelessness about him and, as her eyes grew accustomed to the gloom in the hut, she had an uneasy feeling that there was something wrong with the colour of his skin. It was then that she saw that the umbilical cord was twisted around the child's neck and was pulled so tight that it had virtually disappeared into the soft skin.
     Astra broke the seals on a sterile scalpel that had been placed in the hut in readiness for the birth. She cut the cord in two places and carefully knotted the attached ends before disentangling the cord and holding the infant's head down to drain the fluid from his lungs. There was no reaction from the child: no kicking, no sudden movements of his head, and no sign of the powerful grip that she had learned was normal in newborn babies.
     Sharna stirred and groaned softly. Telson tenderly wiped her forehead while keeping his eyes fixed on Astra as she tried to get the baby to breathe.
     "Baby. . ." Sharna moaned. "Is it. . .?"
     "Everything's all right, my love," said Telson soothingly.
     Sharna tried to struggle up.
     "Keep her still!" hissed Astra.
     "Please, Sharna," said Telson gently, pressing Sharna back onto the furs. "Astra's here. Everything's all right."
     Astra decided to use the emergency treatment that she had read about but never tried. She placed her lips over the child's mouth and nose and blew softly into his lungs. She remembered that the instructions had advocated great care when using this technique because of the danger of causing an embolism in a newborn baby's lungs. She felt the tiny form becoming cold as she held it against her skin and realised that the warmth in its body had been Sharna's warmth. Telson was staring at Astra -- his eyes glazing with shock as he divined the message in her ashen expression.
     Sharna twisted onto her back in an attempt to escape Telson's firm grip.
     "It's my baby! I want to see it!"
     "No, Sharna -- please," pleaded Telson, pushing her back by her shoulders.
     The drug and the birth had drained Sharna's strength. She sank back on the furs and said weakly: "Is it a. . .?"
     "A boy, Sharna," said Astra.
     At that moment the door swung open and Tidy trundled in. He had a brush in place in one of his manipulators. The android took one aghast look at the interior of the hut and said in a petulant voice: "Just look at the dreadful mess you people have made in here. Just look at it. It'll take me hours to tidy up. Hours."
     "You stupid android," snarled Telson. "Get out!"
     "It's tidying time, Commander Telson."
     "I said -- get out!"
     "Only following your instructions, commander."
     "Out!"
     Tidy had 360 degree vision and therefore did not possess a swiveling head that he could have tossed contemptuously. Instead, as he left the hut, he contented himself with: "How you humans can put up with such squalor is quite beyond me. All right. All right. I'm going."
     Astra raised her head from the child and stared at Telson, not knowing what to say.
     Telson nodded slowly and said quietly: "It's this planet."
     "Don't be silly."
     Telson gazed out of a ventilation slit cut into the hut's woven side to where a ribbon of darkening sea was visible. There was the faint sound of laughter from Darv and the children in the neighbouring hut.
     "I tell you it's this planet, Astra. You lost one of your triplets."
     "That was nothing to do with Paradise. And Sharna had no trouble with Bran."
     "Why isn't he crying?" Sharna demanded suddenly.
     Astra cradled the baby in her arms to hide him.
     "He's dead, isn't he?" Sharna's voice was unexpectedly calm.
     Telson looked questioningly at Astra who gave an almost imperceptible nod. He took hold of Sharna's hand and held it tightly.
     "I want to hold him!" said Sharna, pushing herself up on her elbows.
     "We did all we could," said Astra, covering the baby's face with her hand.
     Telson helped Sharna into a sitting position. She stretched out her arms to Astra and the dead infant. "I want to hold him. . . Just for a minute. . . You can't deny me that."

        *  *  *  *
     The Wem's entry into the atmosphere blazed a trail of light across the night sky like a shooting star. At 1000 feet above the ocean, its onboard navigation system took over control from the ship for the final approach. The Wem levelled out, its two stubby wings giving its bloated, white-hot body just enough lift to ensure that it hit the water at the right angle.
     The Wem was the result of 60 days intensive work by the ship's android production workshops. The workshops could normally turn out androids by the hundred each day provided they had the necessary raw materials. Manufacture of the Wem had taken longer than normal because the Wem was not a normal android. Like most planetary landers, it had been designed to withstand the harshest of environments ranging from the vacuum of an airless world to the surface pressures to be found on planets with atmospheres consisting of a thousand-mile depth of methane. There the similarity ended. The Wem was unlike those planetary landers which were designed to gather information. The Wem was very different.
     At 500 feet it scanned the sea below and turned towards the beach so that it would hit the water parallel with the main swell to minimize the risk of damage to itself. It struck the water in a trough between two swells and bounced several times like a skimming stone before coming to rest, bobbing like a wounded fish in the moonlight. Its brain checked all its systems to ensure that all was well before it gave the commands to open the valves and flood the ballast tanks.
     There was a soft bubbling hiss. The Wem started to sink. Five minutes later its obscene black body was submerged and the rolling swells were surging past its radio telemetry antenna. It continued sinking. After another five minutes there was nothing but a fine trail of bubbles to mark the presence on the planet of what was a sophisticated kidnapping machine.

        *  *  *  *
     "Crazy, chimp!" said Darv laughingly as he swung the primate back onto its perch and held an admonishing finger under its nose. "Now you stay there and keep quiet or you're banned. Understood?"
     The monkey took the hint and settled down to watch Darv finish reassembling one of the agricultural android's secondary manipulators.
     "Okay, George," said Darv when the task was completed. "Try that."
     The heavy track-laying machine flexed the manipulator. "Still useless," it grumbled, its harsh, metallic voice echoing in the emptiness of the shuttle's freight bay. "Humans useless at repairing androids. Need proper service unit."
     "Sorry, George. We're not on the Challenger now so you'll just have to make do with me."
     Darv saw a movement and glanced towards the open ramp. Telson was walking along the path towards the shuttle.
     "You'd better get on with your planting, George - the chief is coming."
     "No good expecting miracles from androids," grated George as his multiple electromotors started whirring. Telson stepped to one side on the loading ramp to let the big machine trundle down into the clearing. He watched it disappear into the trees in the direction of the field and moved to Darv's side to help him re-stow the tools.
     "What's the matter with George?"
     "Nothing that new manipulator bearings won't cure." Darv grinned at Telson and added: "If we were to cannibalize this shuttle for spares. . ."
     It was a subject that Darv and Telson had discussed several times during the four years they had been on the planet. Telson's answer was unchanged. An emphatic, "No, Darv."
     "But--'
     "I don't mind you using this freight bay as a workshop, provided you get Tidy to clear up after you, but I still intend to keep the shuttle in first class working order."
     "Also you want George and Tidy kept in first class working order. Well I need spares," said Darv. He added, giving a good imitation of George's grating voice: "No good expecting miracles from humans."
     Telson laughed. It was the first time Darv had heard him laugh since Sharna had lost her baby two months previously.
     "So I can cannibalize the shuttle?" asked Darv hopefully.
     "No."
     "But we'll never need it again," Darv protested. He waved his hands at the cavernous freight bay. "I mean -- look at the size of it. We could all live in here in comfort instead of in the huts."
     Telson glanced around at the broad expanse of floor. It was true that they could live comfortably in the bay, it measured 50 yards long by 8 yards wide, but it was an argument that he had steadfastly refused to listen to.
     "Sorry, Darv, but as soon as we start living in the shuttle we'd lose our respect for it and in no time at all it would become unserviceable. I was the one who brought it down, remember, therefore I think I've a right to decide how we treat it."
     Darv returned the last of the tools to the stowage rack without answering. Telson's entrenched opinion was hard to counter. Not only had he brought the freight shuttle safely down four years previously when they had left the Challenger, but Telson and Sharna brought with them a huge quantity of supplies, including the two androids -- George and Tidy -- and a garment- making android. The smaller shuttle that Darv and Astra used to escape from the Challenger had crashed into the sea with the loss of its supplies.
     "Okay," said Darv resignedly. "You're the boss."
     "That's right."
     "As a matter of interest -- you know full well that there's only enough fuel in its tanks for six climbs into orbit. So what do you think's going to happen? That some alien spacecraft is going to call by? We've survived four years on Paradise so why won't you and Sharna accept it as our home?"
     "This planet isn't Earth, Darv."
     Darv turned to face Telson. "Maybe the Earth we saw in the videos and holograms on the Challenger didn't have a crater-scarred moon; maybe its surface wasn't seven-tenths covered in water; maybe it wasn't the third planet of its sun. But what was so magical about it?"
     "There's no was about it," Telson commented. "The Earth is our true home."
     Darv snorted. "It was somewhere where our grandparents were born that they called Earth." He pointed towards the open ramp and the forest beyond. "This is Earth for us now, Telson. It's reality. It doesn't consist of electronic shadows left on recording machines by people we never knew of a planet we've never seen."
     Telson was silent for a moment. "You're right in some ways," he conceded. "Earth doesn't matter. What matters is people. . ." He regarded Darv thoughtfully. "Aren't there times when you long to see the people of Earth? Our own kind?"
     "I'm happy here."
     "Darv."
     "Well -- yes -- sometimes," Darv amended, responding to Telson's disbelieving tone. He grinned. "But there'll be plenty of new faces when we're grandparents. We might even end up as great-grandparents."
     "Don't be too sure."
     "What's that supposed to mean?"
     "Sharna can't have any more children."
     This was a blow. Darv looked sharply at Telson. "Is she certain?"
     "Well I suppose so," said Telson irritably. "I didn't ask her to go into exact details."
     "Why not?"
     "One doesn't like to pry," said Telson defensively.
     Darv laughed. "You'll never change, Telson. Astra and I discuss everything. We've an agreement -- no secrets."
     The two men walked down the broad loading ramp and into the shadow cast by the huge freight shuttle crouching over them on its landing skids like a giant steel insect. The gleaming flying machine stood in its own clearing because Telson had instructed George to regularly cut back the encroaching vegetation. Darv opened a panel on one of the landing skid's fairings.
     "Come on, Charlie," he called into the freight bay. "Out."
     The chimp scuttled out of the shuttle and disappeared chattering into the forest. Darv touched a control pad and the ramp started to close. The faint hiss of hydraulics stopped when the ramp was flush with the shuttle's silvery outer hull.
     "I would've thought that it was too early for Sharna to tell," Darv observed as he and Telson followed the path through the forest, towards the sound of the breaking surf. "It's only. . . What? Three months since she lost--'
     "She says she's certain," said Telson abruptly.
     "I'm sorry. I know how you both wanted a brother or sister for Bran."
     "Elka and Savin are four now," said Telson.
     "So?"
     "Why is it that Astra hasn't had any more children? She's had four years to get over the loss of one the triplets."
     Darv chuckled. "Can you imagine three kids with all the trouble we're having with the twins? Little devils -- the pair of them."
     "But she is concerned," Telson pointed out. "She's spoken to Sharna about it."
     "Yes -- I know. But Astra would worry if she had nothing to worry about. There's plenty of time."
     "Is there, Darv? Three children between the four of us and so far only one of them a girl? Supposing there's a disaster -- an earthquake -- and only one of them is left? How would you rate our chances of survival?"
     "You're just looking for problems," said Darv dismissively.
     "I don't have to look for them," Telson replied curtly, stepping over a fallen tree. "It's you who's ignoring them. Have you ever asked yourself what sort of future our children have on this planet?"
     Darv began to get angry. "At least they've got a world of their own, Telson. An inheritance. That's a better start than the four of us had -- orphans on the Challenger -- brought up by a couple of megalomaniac computers like Angel One and Two."
     Telson stopped walking and turned to face Darv. "Just suppose that there was an accident that left just one of our children as the sole survivor. The poor kid would be condemned to terrible solitude for the rest of his or her life. Would you like that to happen to Elka?"
     Darv stared back at Telson.
     "Well would you?"
     Darv shook his head.
     "I'll be honest with you," Telson muttered. "I never did like this planet. Sharna's always tried to make the best of it, but her feelings have changed since she lost the baby. Now... She hates it here..."
     As with its two previous reconnoitres, the Wem waited until nightfall before emerging from the sea. It glided stealthily up the beach on silent tracks until it was several yards clear of the surf and stopped to survey its immediate surroundings. It had already learned that the animals on this planet had keen senses and could be belligerent as one particularly large creature had already demonstrated the night before.
     Its infrared surveillance systems swept the terrain. The only animals nearby were those penned in the enclosure near the huts.
     Satisfied that there was no danger, the Wem proceeded further up the beach in search of a good vantage point to make the detailed recordings of the settlement that it would soon be needing.

        *  *  *  *
     Astra woke and discovered that Darv wasn't at her side. He was sitting in his favourite chair -- his first attempt at furniture-making -- staring at the side of the hut. Charlie was also awake -- sitting upright in his giant clam shell that served as a bed -- grunting softly to himself. She listened for the regular breathing of the twins on the far side of the partition before speaking.
     "Darv?"
     "Mm?"
     "Come to bed."
     "In a minute."
     Astra pushed the pelt bedcover aside and moved behind Darv, snaking her arms around his neck. "What are you doing?"
     Darv covered her hands with his. "Thinking, my lovely."
     "What about?"
     "Oh. . . Maxina must've had her cubs by now. I was wondering if she might bring them to us."
     "She always does. Anyway -- you weren't really thinking about that lioness were you?"
     Darv squeezed her hands affectionately. "No."
     Charlie became alert -- bouncing up and down and chattering to himself. Astra knelt down beside his bed and calmed him down before sliding across the matting floor and resting her head on Darv's knee.
     "So what were you thinking about?" she asked. "No secrets -- remember."
     Darv briefly outlined his conversation with Telson.
     "I thought Sharna had got over the shock by now," said Astra when Darv had finished. "Obviously she hasn't. Telson's not very understanding, so I don't suppose he's much help. Anyway -- maybe it'll be better if she doesn't have any more children if they're going to be like Bran."
     Darv looked puzzled. "I don't understand."
     "That boy is a sadistic little monster."
     Astra's vehemence surprised Darv. "A three-year-old?" he queried.
     "Listen a minute!" Astra turned her head towards the beach and listened intently. Charlie chattered again while looking fearfully towards the door. Astra waved a hand impatiently at him to be quiet.
     "What's the matter?" asked Darv.
     "Listen!"
     Darv listened. There was only the distant roar of surf.
     "I thought I heard something moving on the beach. . . It's gone now."
     "Probably Tidy."
     Astra accepted Darv's possible explanation. Tidy even hated his owners making fresh footprints in the sand and had been known to labour through the night trying to brush the beach smooth even though he wasn't programmed to work after dark.
     "You were going to say something about Bran?" Darv prompted.
     "That newly hatched chick he killed last month -- it wasn't an accident -- he did it deliberately."
     Darv was about to protest but Astra cut him short. "I saw him do it, Darv. He didn't tread on it, he stamped on it. Elka was nearby and she was horrified."
     "But he was upset afterwards. He was crying."
     "Because he realised that I'd seen him. He's clever."
     "Did you tell Sharna?"
     "What would be the point? Anyway, I didn't want to add to her worries."
     "All kids are monsters," Darv observed. "When I was Bran's age, my old nursery android on the Challenger was always telling me how awful I was."
     "Savin or Elka would never do anything like that."
     Darv grinned. "Can you blame them? With you telling them that Angel One and Two will get them unless they're good? You shouldn't frighten them with those stories."
     "They enjoy them," said Astra firmly. "And besides -- it's important that they're told about the angels. . . Just in case."
     Darv broke the brief silence that followed. "We ought to have more children."
     "Not until the twins are older. Two give me enough headaches as it is." Astra stood and pulled Darv to his feet. "Come on. Tomorrow's a busy day."
     Darv was still awake ten minutes later -- staring up at a chink in the roof where the moon was shining through. It was a reminder that the roof would have to be rethatched before the onset of the wet season -- one of a seemingly endless series of jobs that needed to be done in the next few weeks. His thoughts turned again to the conversation earlier that day with Telson.
     "Astra. . ."
     "Try to sleep."
     "It all seems like a lifetime ago since we were on the Challenger. . . Do you think we did the right thing - coming here?"
     Astra put an arm around Darv and pulled him close while she considered her answer. "Sometimes -- when it's cold, and the when the fire won't burn properly because the wood's too wet -- that's when I think back to my warm, comfortable cabin on the Challenger. And then, when I watch Elka and Savin playing in the sea -- building sand castles -- laughing, that's when I think what might've happened to them if Angel One and Two had them under their control. . . We did the right thing, Darv. There was nothing else we could do. . . Except for one thing. . ."
     "And what was that?"
     There was an uncharacteristic hardness in Astra's voice when she replied. "If we had discovered the computers' central switching room and not Telson and Sharna -- then I wouldn't've hesitated in destroying Angel One and Two -- no matter how hard they begged us to spare them."
     Darv sighed. "Well what does it matter now? After four years they and the Challenger will be billions of miles away by now."
     "I hope so."
     Darv yawned. "They're busy looking for the real Earth. They want a developed planet to conquer. I don't suppose they even think about us now."
     "I hope not, Darv."
     There was no answer: Darv was asleep.

        *  *  *  *
     The dawn light filtered down through the tepid, transparent depths to where the Wem lay on the sea floor, its grotesque body half-buried in a forest of seaweed that curled and heaved in time with the suck and drag of the crashing rollers breaking on the nearby beach. The weak sunlight shining on its photosensors produced a tiny electric current, which, when amplified, was enough to wake it.
     The Wem carried out a series of tests on all its complex systems and decided that the time had come for it to move into shallower water in order to fulfill its task.

        *  *  *  *
     "Bran!" shouted Sharna angrily, shading her eyes against the early morning sun. "You're to stop throwing sand at Elka and Savin!"
     Bran was standing up to his ankles in the surging tide, threatening the twins with a handful of oozing, wet sand. He pointed an accusing finger at Elka who was staring at him.
     "Started it!" he cried defensively. Despite his view that Elka was to blame, he promptly hurled the splat of wet sand at Savin.
     Sharna angrily splashed into the sea, gave her unrepentant son a resounding smack across the buttocks and dragged him out of the water by his arm. She thrust him down on the hot sand and glared at him. She walked up the beach to where the others were finishing breakfast in the shade of one of the huts.
     "There's a vicious streak in that child," she declared, sitting down and picking up her half-eaten pineapple.
     "Well he didn't get it from me," said Telson. "Tidy!"
     The android trundled forward.
     "What do you want?"
     "You can start clearing away now."
     Tidy jabbed a manipulator at some dark stains on the sand where some goat's milk had been spilt. "And what about that? How am I supposed to clear up that mess? And it's no good you trying to bury it. I'll still know it's there." With that the fastidious android gathered up the homemade earthenware bowls and went off muttering to himself.
     Astra shaded her eyes and noticed that Savin was swimming further from the beach than she considered safe.
     "Right," said Telson briskly, checking some notes he had written on an everlasting pad. "Time for the morning briefing."
     Everyone looked bored. The after breakfast discussions were a daily ritual that Telson had insisted on observing ever since they had settled on Paradise.
     "Today is Year Four, Day Ten," Telson stated. "Agreed? Astra -- I checked the calendar trees first thing this morning. You're four days behind with the notches."
     "Go and speak to Savin," said Astra to Darv. "He's going too far out."
     Darv twisted round and watched the bobbing head in the sparkling sea for a moment. "Oh he's okay -- he's turning into a strong little swimmer."
     "The briefing," said Telson icily.
     Darv grinned at him. "Sorry."
     "You'll bring the calendar trees up-to-date today, Astra?"
     Astra gave Telson a sweet smile. "Of course, commander."
     Telson made a neat tick against an entry on his pad.
     "Oh look, Telson," said Darv. "Let's take the chronometers out of the shuttle. They'd last for eternity."
     "We leave all the shuttle's fixture where they are," Telson replied emphatically. Carving a notch on a tree each day isn't much to ask, is it, Astra? Any reports, anyone?"
     "The new salt pan George has excavated isn't large enough," said Sharna. "It's producing just enough salt to fill a size One bowl each day. We'll need twice that for salting vegetables for the next dry season."
     Telson made another note. "Okay. We'll get George to excavate a larger salt pan."
     "We ought to do it ourselves," said Darv.
     "What's the point when we've got George?" Telson inquired. "That's why Sharna and I brought him with us."
     "Because it's time we stopped depending on the androids. They won't last for ever. How can we hope to teach our children how to manage without them when we don't know ourselves?"
     "That's right," said Tidy who was eavesdropping from his favourite sulking position. "I don't how you can expect me to carry on with this manipulator joint. What with cleaning up after your animals, and the sand and dirt getting everywhere."
     Telson counted up to ten. "Tidy -- will you please be quiet!"
     "It's all right for you, commander. Sand doesn't get into your bearings." He waved a manipulator joint that was a sloppy fit where it was connected to his trunk. "Just look at that -- well I ask you. And you're all forever. . ."
     "Tidy," said Sharna warningly.
     ". . .treading sand into the huts -- ruining my nice clean mats. I really don't know why I bother to weave them. They make such a mess when they unravel-'
     Telson jumped to his feet. "Go away before I turn you into a mess!"
     "Sorry I spoke," Tidy muttered, moving off. "No pleasing some humans."
     "We should've left him on the Challenger," Telson growled.
     "He can cook and he keeps the place clean and tidy," said Sharna.
     "And he's right about that manipulator joint," Darv added. "The main bearing's badly worn. If I could remove one of the electric motors from the shuttle's hydraulic systems, I could rig-up a lathe and make him a new bearing."
     "No," said Telson curtly.
     "Darv," said Astra worriedly. "Go and speak to Savin. He takes more notice of you."
     "In that case," said Darv, taking no notice of Astra, "we'll have to close down George and Tidy and learn to live without them."
     "You're being idiotic," Sharna commented.
     Darv sighed. "The longer we leave it, the harder we're making it for ourselves when the androids pack up for good. They were designed to operate in the conditions aboard the Challenger --not under the conditions we get here."
     "George is an agricultural unit," Telson pointed out. "He worked satisfactorily in the Challenger's farm galleries."
     "You didn't get thirty days of continuous rain in the farm galleries," Darv shot back. "Last wet season he was working in mud up to the top of his tracks when he was clearing the new field."
     Sharna noticed that Bran had disobeyed her and was back in the sea - chucking sand at Elka. "Little devil," she muttered.
     "Life's uncomfortable enough on this damned planet without you wanting to make it even moreso," grumbled Telson.
     Darv stared incredulously at Telson for a moment and gestured at the flawless blue sky and azure sea. "You really can find fault with all this?"
     "We could never plough fields or dig irrigation trenches or do any of the thousand and one jobs that the androids do," said Telson, adding pointedly: "And if we ate some of those animals instead of keeping them as pets, we wouldn't have to grow so many vegetables which also means that we wouldn't be so dependent on the androids."
     There was a sudden, shrill scream from the children. It was not the scream of children's play, but one of abject terror. Elka run out of the sea sobbing hysterically.
     "It's Savin!" cried Astra, jumping to her feet. "He's disappeared!"

        *  *  *  *
     It was dark when Telson entered his and Sharna's hut. He sank tiredly into a chair and kicked off his sandals. His feet were raw and blistered from exposure to the sun.
     There was no need for Sharna to ask how the evening's search had gone because his haggard expression told its own story. All through the long day the four adults had worked in relays in the burning sun in a fruitless search for Savin. Darv and Telson had spent most of the afternoon diving down into the depths from the log raft and had only stopped when forced to do so by aching ears and exhaustion.
     Sharna poured out a mug of fruit juice and gave it to Telson without being asked. He sipped it gratefully.
     "How are they?" he asked.
     "Sleeping. I insisted that they both took a heavy dose of morphon." Sharna nodded to the partition. "Elka's in with Bran for tonight."
     Telson nodded.
     "It hasn't really hit her yet, but it will tomorrow," said Sharna. She yawned. "I only hope I'll be able to sleep. This has been the longest day of my life."
     Telson pulled on his sandals and stood. "I'd better check the beach again."
     "Oh sit down -- we can do it together first light."
     "If Sav-- If. . . well -- anything is washed up, I don't want them finding- -'
     "We'll be up before them," Sharna interrupted. She looked searchingly at Telson. "Did you get anything out of Bran when you spoke to him?"
     Telson hesitated while he marshalled his thoughts. He was uncertain how to begin. "Sharna -- you may think I'm crazy, but I don't think he was in a state of shock."
     "Well of course he was -- Savin being taken by a shark right under his nose like that."
     "It wasn't a shark," said Telson. "There's still no way a shark could get this side of the sandbar. Darv and I checked every inch of it. I don't know what it was, but I do know that Bran wasn't in a state of shock -- at least not once he realised that he wasn't being blamed for what happened -- not that it stopped him making up one of his stories."
     "What did he say?"
     "That Savin was about five yards away when suddenly he grew a new head."
     "What!"
     "Wait until you hear the rest of it. He said that Savin grew a new head and then a steel claw went round Savin's waist and pulled him underwater."
     Neither spoke for a while.
     "And that's all?" queried Sharna.
     Telson nodded. "And then he wanted to know if Angel One had snatched Savin."
     "Poor Bran," muttered Sharna.
     "Why?"
     "Well it's obvious, isn't it? Bran's definitely in a state of shock. Why else would he make up such an incredible story?"
     Telson shook his head. "Let's face it, Sharna. Bran doesn't have to be in a state of shock to invent incredible stories."
     Sharna was lost in thought for a few moments and then she came to a decision. "All right," she said, pulling on a jacket and a pair of trousers. "We'll check the beach now. There's a full moon so we won't need a lantern, and it'll give me time to think."

        *  *  *  *
     It took Sharna and Telson an hour to reach the mass of half-buried boulders that marked the northern extremity of the two-mile wide bay. Nothing had escaped their attention during their careful search of the tidemark; every suspicious-looking pile of seaweed or water-sodden log on the broad sweep of moonlit sand had been investigated by them -- their emotions a mixture of fear and hope - - and they had found nothing.
     "I suppose we could check along there," said Telson, pointing to the fountains of silvery spray that garnished the foot of the cliffs.
     "It'll be too dangerous at night," said Sharna practically.
     Telson heard a faint whirring sound and quickly pulled Sharna into the shadows afforded by a pile of massive boulders.
     "What's the matter?" she asked.
     "Shh! Listen."
     They both listened intently but all Sharna could hear was the sea exploding against the cliff. She was about to say something when she too heard a sound that didn't belong. It was a soft, swishing sound followed by a brief whirring noise. Then silence again. When it was repeated, it was much nearer -- heading towards them. She took a hint from Telson and flattened herself against the boulder, her heart thumping wildly. The noise drew nearer until the machine, or whatever it was, suddenly stopped as if it had seen them.
     "You two have made nasty footprints all over my beach," said Tidy's accusing voice. "I really don't know why I bother sometimes."
     Telson and Sharna emerged from their hiding place and surveyed the android with a mixture of relief and dislike. It was clutching a besom in a manipulator and regarding them with the androidal equivalent of straightforward loathing.
     "Tidy," said Sharna, trying to keep her voice steady. "What are you doing?"
     "Trying to keep the place tidy. What does it look like?"
     "At this time of night?" inquired Telson.
     "Your orders, commander. Keep the place tidy. I have to work all hours if I'm to keep on top of everything. Though I've given up with the jungle. You can't keep a jungle tidy what with all the birds, and things growing all the time."
     "But you've never worked at night before without specific programming," said Sharna.
     "I've never had a hulking great android tramping all over my beach at night before."
     Telson frowned. "But George doesn't work on the beach."
     "Track marks up and down the beach," continued Tidy indignantly. "Every night. It just doesn't care."
     "What android?"
     "The one that tramps up and down my beach every night."
     Telson rested a hand against the boulder and prayed for a measure of patience.
     "How long has this been going on for?" asked Sharna.
     "Four nights."
     "Where do the marks come from?"
     "The sea."
     "And they go where?"
     Tidy pointed in the direction of the huts. "About fifty yards up the beach."
     "Always at the same time each night?"
     "I think so. Look -- it's no good you lot going on at me. I'm doing my best to keep this place tidy. I can't help it if a stupid android--'
     "No one's going on at you," Telson snapped.
     "But why bother to keep the beach clean?" Sharna queried. "At this time of the month the tide would've wiped out the marks before dawn so we would never have known about them."
     "I would have known about them," retorted Tidy with great dignity. "And it's getting worse. Tonight they went right up to the treeline. It's a wonder I've not worn out my brush."
     "Where?" said Telson sharply. "Point."
     Tidy pointed to the dense vegetation beyond the huts.
     There was a pause and then Sharna said: "This time we will need a lantern."

        *  *  *  *
     It was three hours before dawn when Sharna and Telson found Savin's body by following the strange track marks in the soft ground beneath the trees. A strange design of breathing mask had been pulled back-to-front over his head and his waist bore marks that could have been made by an android's manipulator.
     Sharna held the lantern up while Telson turned the tiny body over. There were more of the regular marks across Savin's back.
     "So Bran was telling the truth," breathed Telson as he straightened up and stared down at the pathetic sight. "Poor little mite."
     "What do we tell Darv and Astra?"
     Telson shook his head slowly. "I don't know. What I do know is that someone or something tried to kidnap Savin and killed him in the attempt." He met Sharna's gaze. "It means that we're not as alone on this planet as we thought."

        *  *  *  *
     Darv, Astra, Sharna and Telson had been born on the Challenger and, because their parents and all the other human members of the starship's crew had been killed shortly after their birth, they had known no influence during their formative years other than that of Angel One and Angel Two. Despite this, they knew from the videos and holograms in the Challenger's library that their forebears had worshipped a deity that they believed to be responsible for the creation of the Universe.
     Once the four had discovered that this deity was not the combined force of the Angel One and Two, each had independently, and some cases, painfully, come to accept the simple beliefs of their parents: that there was a God that was beyond all understanding. If that God cared for the mortals he had created, they did not know; if there was such a thing as a soul, they did not know; if there was a life after death, they did not know.
     But as they gathered around the tiny open grave in a clearing in the strange forest on a planet belonging to an obscure star on the fringe of the galaxy, it gave them a collective comfort and a strange, indefinable inner warmth, to believe that such things were within the realms of possibility. Nor did they know if the simple words that Telson recited over the grave before the dark soil cascaded onto matting-wrapped bundle would in any way help bring these things about. But they wanted it to be so. When such slender beliefs are born in adversity, instead of those feelings of bitterness --that is when the seeds of enduring faith are sown.
     When all the soil had been returned to the grave, they stood quietly for a minute while the life of the forest -- its birds and flying insects -- pulsed around them. Even Bran and Elka remained still and quiet, holding their parents' hands.
     At length Telson spoke. "I hope I didn't leave too much out," he said awkwardly. "It was as near to the recordings of burials as I can remember. We'll plant the tree next week -- when the soil has settled."
     "You did very well," said Astra. "Thank you."
     Without a backward glance at the grave, they filed along the forest path back to their settlement.

        *  *  *  *
     Over the midday meal Telson said: "From now on we never let Bran and Elka out of our sight, and we don't let them go in the sea -- not even to paddle. I'll work out a rota so that one of us is always watching them. Whoever it is wears a PD weapon all the time. Agreed?"
     There was a murmur of assent but not from Astra. "We've got to do more than that," she said quietly. "We've got to find and destroy the machine that killed my son."
     Telson looked up at Darv. "You'd better tell her."
     Darv took hold of Astra's hand and said gently: "Telson and I are taking the shuttle up this afternoon for an aerial survey of the entire area. If we find anything, we'll destroy it -- I promise."
     Astra's face creased in anxiety. "No, Darv -- I don't want you to leave me. Not so soon. . ."
     Darv kissed the palm of her hand. "There's not a wisp of cloud today, my love. We'll only be gone for three hours, and we'll leave you and Sharna a mobility suit radio to keep in constant touch."

        *  *  *  *
     "Hi-gravity boosters?" called Telson, reading off from the checklist that was displayed on the control desk screen.
     "Hi-gravity boosters -- on," said Darv boredly as he touched out the initiation codes on the co-pilot's console. The laborious pre-flight checks had been going on for fifteen minutes. Normally they weren't necessary because the shuttle's flight and navigation computers would prevent the machine taking off if any of its systems were malfunctioning. Telson -- always the cautious one -had insisted on a complete manual check just in case the four years inactivity in sub-tropical conditions had affected the shuttle in any way.
     ALL SYSTEMS CONDITION GREEN appeared simultaneous on Darv's screen and Telson's screen.
     "Fine," said Telson. "I'll load the inertials for a five minute hover at four thousand feet. Ready?"
     Darv nodded.
     "Ready?" Telson repeated testily.
     "Ready!" Darv snapped back. "The damned thing can fly itself, so why the charade?"
     Telson said nothing. His fingers moved over the touch-sensitive controls and the shuttle's chemical rocket engines came to life with a dull roar. The thrust built up rapidly. The displays that indicated the shuttle's weight winked to zero and then the unladen machine lifted smoothly above the treetops.
     Downward visibility from the flightdeck -- perched on top of the shuttle's bulbous body -- was not good in level flight therefore Telson banked the machine and allowed it to gain altitude in a slow, spiralling climb that gave both men a good view of the ground immediately below through the viewports on Darv's side.
     "Beautiful," breathed Telson as he tested the controls. "You see? I was right to maintain her in good working order." He was particularly pleased that his fears about possible evaporation of fuel had been proved groundless -- the totalisers showed the tank contents to be eighty-two per cent -- the same figure as when he and Sharna had landed the shuttle on Paradise four years' previously.
     The heady sensation of flying again helped Darv to forget about Savin for the time-being. He spotted Astra and Sharna on the beach, staring up at the shuttle. Bran and Elka were standing nearby. Elka waved. The field system of ripening cereal crops that George was tending was a conspicuous square of gold amid the greenery. Half a mile to the West of the settlement lay Land Mark Hill -- its rounded, grass-covered slopes rising above the dense forest. The four tethered goats grazing on the lush grass paid no attention the roaring shuttle above their heads.
     To the East the blue horizon dividing sea and sky receded as the shuttle climbed.
     Telson touched Darv's elbow and pointed through one of the forward viewports. A family of elephants led by a bull with one tusk was crossing the stream about five miles from the settlement. "Looks like Bok is paying us one of his periodic visits," he observed.
     Three years before, Darv had found the big elephant lying in the bush, half-dead from the effects of a fight -- possibly with another bull. Some simple but effective surgery and a dose of antibiotics had saved the creature's life. Since then, in common with many other wild animals, Bok had become a frequent and welcome visitor. On each occasion, the old bull would nose around the clearing --examining every new structure with his sensitive trunk -- before slinking back into the jungle as quietly as he had arrived.
     The great beast's friendship reflected the rapport with nature that the four had established soon after their arrival on Paradise. Whether it was because they had opted for a predominantly vegetable and fruit diet, they did not know. But the wildlife had quickly recognised that the four new arrivals did not pose a threat, and a surprisingly large number of animals - such as the goats - had shown a remarkable willingness to be tamed.
     "Top of climb -- four thousand feet," said Telson. "Let's start searching."
     All the shuttle's ground surveillance systems were switched on.
     "Let's have the radar on as well in case it's a flying machine," Darv suggested.
     Telson agreed, switched on the radar systems and called up Sharna.
     "Go ahead, shuttle," Sharna replied.
     "We're starting a five-minute search now."
     "We can see and hear you, shuttle. Good luck."
     Despite a meticulous search for marks on the landscape that even remotely resembled the marks that had been found near Savin's body, the two men found nothing. They even studied the terrain below in the infrared spectrum in case the machine had left a thermal wake. But there was nothing.
     "We'll take her over the sea for a minute," said Telson. "From this height we can ought to be able see down to a depth of at least two-hundred feet."
     He was about to operate the controls when the radar hazard alarm emitted a shrill whistle. Darv quickly cut the alarm and read out the figures that had appeared on his display:
     "Bearing zero one. . ." said Darv, trying to keep the excitement out of his voice. "Elevation three five. . . It's well above the horizon."
     "Lock the optical telescope onto it," Telson ordered.
     Darv touched out the settings. The flight information data cleared from the screen in front of the two men and was replaced by a blank picture of clear blue sky. There was an indistinct dot in the precise centre of the screen. Darv tried to sharpen the image but the object was too far away. The shuttle's radar computers proceeded with an analysis of the object and printed out their findings along the foot of the screens:
     RANGE - 15 000 MILES.
     HEIGHT ABOVE SURFACE - 8000 MILES.
     LENGTH - 14 000 YARDS.
     DIAMETER - 1 000 YARDS.
     FLIGHT MODE - 40 DEGREE INCLINED EQUATORIAL ORBITAL.
     ORIGIN - NO INFORMATION. SYMMETRICAL CONFIGURATION SUGGESTS OBJECT TO BE ARTIFICIAL.
     Darv and Telson exchanged stares and returned their attention to their screens.
     "It's the Challenger," Darv whispered.
     Telson shook his head. "It's much too small -- the Challenger was ten miles long, not seven."
     "We've got to take a closer look at it," Darv declared.
     "The fuel-'
     "We've got plenty of fuel! We have to find out what that spacecraft is!"
     Telson hesitated and then opened the communication circuit.
     "Sharna."
     "Go ahead, shuttle," answered Sharna's voice.
     "Sharna, we've found something so we're going to investigate. It means going into orbit so we'll be below the radio horizon for about three hours."
     "What is it?"
     "We don't know yet," said Telson. "We'll call you in three hours." He cut the circuit without waiting for an answer. "Saves a lot of argument," he muttered in answer to Darv's questioning look. "Okay, Darv, pressurise the flight deck, close the micrometeoroid shields on the passenger cabin viewports, and load the inertials for a matching orbit with that thing."

        *  *  *  *
     For a few seconds Sharna and Astra risked diverting their attention from the children playing on the beach while Tidy kept watch on them. The two women shaded their eyes against the glare of the sun and watched the hovering shuttle as it lifted its nose. The whine of its engines rose to a continuous howl and the vectored thrust outlets vomited dense, billowing clouds of white exhaust gases. By the time the clouds were dispersed by the light breeze, the shuttle was a dot boring vertically into the blue, the roar of its engines dwindling rapidly to a muted, reverberating thunder that echoed around the bay.

        *  *  *  *
     The mighty ship moved black and silent along its orbit above Paradise, ignoring the diminutive shuttle that had matched orbits with it and was slowly closing the fifty mile gap between the two craft.
     "She looks new," observed Darv, studying the image on the screen before him.
     "Hallo, spacecraft," said Telson for the tenth time. "Are you receiving me?"
     As before, the only reply from the repeater speaker was the hiss of white noise. Telson gave a sigh of exasperation and closed the communication circuits. "Well they're not maintaining a listening watch."
     "Or she's listening but not answering," Darv commented.
     "What do you think of her?"
     "Impressive. Those particle sweeps haven't seen much use."
     "Which means that she could be near her home planet," said Telson.
     "She's not using radar," said Darv. "There's nothing on the radiation monitors.
     The two men studied the mysterious ship for two minutes without speaking.
     "So what now?" inquired Darv.
     Telson thought for a moment before answering. "Well we can't make out any fine detail at this range so we might as well wait until we're closer."
     Darv looked worried. "You think that's wise? Going closer?"
     Telson smiled. "It's not like you to counsel caution."
     "She might not be talking to us because they've decided that they can't stand the sight of us. And if she's that new -- maybe they're itching for a chance to try out their armament?"
     "Let's get within ten miles of her and try calling her up again," suggested Telson.

        *  *  *  *
     The Wem lay still on the seafloor.
     It was in less than twenty feet of water and within fifty yards of the shore which meant that it was obliged to anchor itself to a submerged rock with its powerful claws to prevent the eddies set up by the breaking waves from moving it about. It would have preferred to have hidden itself in the forest of kelp that carpeted the seafloor in the deeper water on the far side of the sandbar. It was the change in tactics of its prey had forced it to change its plans.
     The Wem was puzzled: each day its sensitive microphones had registered the sounds made by the humans as they moved about in the water, and it had made its plans accordingly. Today they were making similar noises but they were staying out of the sea. Perhaps it was something to do with its abortive first attempt of the day before. The Wem did not know, nor did it have the intelligence levels to puzzle such things out. All it knew was that the humans disappeared at night and that the sun had already passed its zenith. Therefore, if the humans did not come to him, he had no choice but to go to them.

        *  *  *  *
     The shuttle had moved close enough to be dwarfed by the mighty ship, and still it continued to ignore them despite Telson's attempts to contact it by broadcasting on every channel.
     Steered by short bursts from it directional thrusters, the shuttle moved along the ship's curving flank like a gnat exploring an elephant.
     "There's no doubt that she's new," Darv commented. "Look at her skin, no particle erosion, no scarring, nothing."
     Telson had nothing to add. What Darv said was true: the ship could not possibly have done much travelling at near the speed of light, a velocity at which, judging by the size of her furled particle sweeps, she was obviously designed for. The ship's black outer skin was flawless in every respect.
     Darv guided the shuttle towards the ship's yawning photonic drive outlets and into its darkside where its stupendous bulk obscured the sun. Telson switched on the shuttle's forward floodlights. The brilliant lamps bathed one of the ship's giant wing-like heat dissipation fins. Both men sucked in their breath in astonishment at what the lights revealed. Etched on the flat surface of the cooling fin in large white letters was a huge sign that read:
     VOYAGER 30
     Underneath in smaller letters were the words:
     23RD EARTH TRANS-GALACTIC SURVEY MISSION.
     Darv was the first to speak when both men had recovered from their initial shock:
     "Well," he said with an air of resigned finality. "We don't have to worry about searching for Earth anymore. Earth has found us."

     Part Two Flood.

     Sharna and Astra heard the strange sound at the same time. They simultaneously snatched their PD weapons from their holsters and pointed them at the trees.
     Sharna gave a nervous laugh of relief and lowered her weapon when she saw the cause of the noise, a bull elephant with one tusk, moving sedately down the beach towards them. She holstered her firearm and Astra did the same. "Now what," Sharna commented caustically, "do you suppose Bok wants?"
     "He's limping," observed Astra, and then she saw the deep, crater-like wound in his foreleg above the knee.
     The great single-tusked beast stopped before the two women and regarded them with aged, thoughtful eyes, his huge ears spread wide and his long, sensitive trunk reaching out to gently caress Sharna's and Astra's face in turn.
     "Watch the children, Tidy," Sharna instructed, handing the android a PD weapon.
     Tidy was not pleased to see Bok. He stood beneath the creature that was towering over him and announced that he, personally, would throw the elephant off the beach if it dared to make a mess.
     "Just be quiet and watch the children," Sharna snapped angrily. She turned her attention to Bok's injury. "It's a burn all right, a bad one too. . . Still -- nothing that some tissue regenerator can't cure". She looked up at Astra. "It might take a little time. You've had a long day, so if you'd rather go and rest.
     Astra shook her head. "I'm all right, Sharna -- really. I'd like to help. I'd rather have something to take my mind off. . ." She hesitated. "You understand?"
     Bok didn't move when Sharna carefully probed the raw flesh. It was a strange injury, there was no damage to the surrounding tissue such as might be expected from an encounter with a crocodile. It was as if the flesh had been neatly dissolved in the one spot.
     "A burn?" Astra queried, wondering how the elephant could tolerate the pain it must have been in with such stoic silence.
     "Possibly. And yet Bok and his herd always stay well clear of our fires. They're never away for much longer than a week, and we haven't had a forest fire for two years."
     "And a forest fire burn wouldn't be so deep and in just one place," said Astra, studying the injury more closely and ignoring Bok's trunk that was sliding affectionately up and down her spine. "Sharna, it's been caused by a plasma discharge -- someone has fired a PD weapon at him."
     At first Sharna was inclined to scoff and then she realised that Astra could be right: the burn looked exactly like a PD injury. She frowned. "But who would've done such a thing? Telson may not be over-fond of any of the animals but he wouldn't shoot one of them. And Darv certainly wouldn't."
     "Do you keep your PD weapons out of Bran's reach?"
     Sharna looked sharply at Astra and said, slowly and deliberately: "What are you trying to tell me, Astra?"
     Bok stirred restlessly. Sharna calmed him and repeated her question to Astra.
     "You said yourself that there was an aggressive streak in him," Astra replied defensively.
     Suddenly Bok lifted his trunk and trumpeted angrily. Narrowly avoiding the women and Tidy, he charged down the beach in the direction of the two children. Despite his great bulk, he moved with incredible speed, his huge feet pounding the baked beach, raising four wakes of swirling sand.
     Sharna was the first to recover from the shock. She was a second ahead of Astra in dragging her PD weapon from its holster. She aimed at Bok and was about to fire when she saw that the great beast had passed the children and was heading straight at a monstrous apparition that was rising out of the sea.

        *  *  *  *
     Telson was reluctant to take the shuttle any nearer than 200 yards of the mysterious black starship. He and Darv could do nothing except study the ship in complete bewilderment. There was no sign of life from it, none of the excursion doors were open, and the shuttle's radio receivers remained eerily silent.
     "Maybe the crew are in suspended animation," suggested Telson as he and Darv debated the enigmatic spacecraft.
     "Surely they would've been revived before going into orbit around our planet?"
     Telson shook his head, baffled. "The really odd thing is the design similarities between this ship and the Challenger -- the photonic drive housing is virtually identical."
     There was a low hiss from the repeater speaker followed by a female voice. "This is Earthship Voyager 30 to spacecraft. Please identify yourself before approaching any closer." Despite the proximity of the shuttle to the strange ship, the voice was indistinct and distorted.
     Telson concealed his excitement and calmly opened the communication channels. "Hallo, Voyager 30. This is shuttle. You're breaking up but understood. We are the descendants of a survey ship crew that left Earth one million years ago. Until we settled on this planet, we had been searching for Earth."
     There was a pause before the barely readable female voice replied. "Wait please, shuttle, while we check your craft's configuration against records." The speaker went dead.
     "All that searching!" said Darv elatedly, grinning broadly at Telson. "All that trouble with Angel One and Two -- and Earth finds us!"
     Telson innate caution asserted itself. "They may not believe us if their records don't go that far back," he warned.
     "They've got to believe us! They speak our language."
     "We speak their language."
     The speaker came to life again. Despite being garbled, it was possible to distinguish a more friendly tone in the voice. "Hallo, shuttle. This is Voyager 30. We have identified your spacecraft as a type of shuttle designed for the Challenger Class survey ships of the Third Millennium. How many are there in your party?"
     "There's six of us altogether," Telson replied, thinking that the voice was referring to the population of the Paradise settlement rather than the number of those aboard the shuttle.
     "Thank you, shuttle. How old are the children?"
     Darv looked puzzled. He was about to say something but Telson had already answered the question with: "One is four years old and the other is a little younger. Our year is equal to--'
     "What sexes are they?"
     "One boy and one girl," Telson replied. "Why the interest in our child--'
     "Our facilities for your children are limited," the voice cut in, "but we will do our best, and our commander is looking forward to meeting you. We are opening the doors to our main shuttle excursion terminal. Message ends."
     Telson sat back in his seat and looked at Darv. "The moment of truth."
     Darv nodded. "Well let's hope that they don't mind the misunderstanding. They seem to be under the impression that we're all on board." He stiffened and pointed.
     A brilliant white slit had appeared. The slit gradually widened and the two men realised that two large doors, shaped to matched the curvature of the black ship's hull, were sliding slowly open.
     Telson kept the forward lights burning and guided the shuttle into the ship's interior. The excursion terminal was brilliantly lit but, like the ship's exterior, was black and featureless. It was large enough to have comfortably accommodated 10 shuttles and yet -- as Telson swung the hovering shuttle around in circle --there were no other craft in evidence. The excursion terminal was one vast, empty cavern.
     The doors slid shut and Darv and Telson sat perfectly still, wondering what was going to happen next. The external environment indicators showed that gravity was being generated within the terminal and this was confirmed a moment later when the shuttle settled on its landing skids with a gentle bump. The introduction of an atmosphere was confirmed by a swelling roaring sound that continued for several seconds until the displays were showing an external pressure of one atmosphere. When the noise stopped the two men could hear strange, faraway music that rose and fell like a soft summer breeze.
     "What do you make of that?" Darv queried.
     Telson shrugged. Darv was about to close down the shuttle's power supplies but Telson stopped him.
     "Leave the inertial navigation computers live otherwise they'll lose our position references. You can shut down the artificial gravity and the air- conditioning."
     "Okay," said Darv, following orders and then releasing his seat restraint harness. He glanced through the view ports at the forbidding bulkheads and spotted the faint outline of several airlock doors. "They don't seem very quick off the mark with their welcoming committees," he observed. "Now what?"
     "We'll take a look outside but we'll wear PD weapons."
     "Oh come on, Telson," Darv protested. "We're on an Earth ship, we can't go down the shuttle's steps waving PD weapons about."
     "I said wearing them, not holding them."
     Darv won the argument and a minute later both men moved aft into the deserted passenger cabin and went cautiously but unarmed down the shuttle's long flight of folding steps. They stood at the foot of the steps, listening to the gentle hum of the strange music and waiting for something to happen. The lights in the terminal were flickering erratically. They called out several times but no-one answered.
     Telson stooped down and examined the floor. "Similar material to the excursion terminal floors in the Challenger," he commented. "And very poor welding at that. Look at this seam."
     "So where's the reception party?" Darv complained. "I want to fall into someone's arms and be greeted as a long-lost brother."
     "Don't chuck your sense of humour about too much," Telson warned. "They may be watching and listening and decide they're better off letting you remain lost." Despite the humorous response, Telson's frowning expression indicated that he was concerned about their curious situation.
     At that moment the music stopped and the lights began burning steadily.
     "Darv," said Telson uneasily. "I don't like this place. I think we should leave."
     There were times when Telson's caution drove Darv to despair. "Oh for God's sake, Telson--'
     Darv got no further because he was interrupted by a voice that he hadn't heard in four years except when it returned to haunt his nightmares. It was the female voice of Angel One:
     "Hallo, Commander Telson. Darv. Welcome back to the Challenger."

        *  *  *  *
     The Wem had encountered the elephant before but this time it was unsuccessful in dealing with the huge beast. It fired three plasma discharges into Bok's chest and head but the enraged creature was upon it before it could fire a fourth bolt. With blood gushing from his terrible wounds, Bok's momentum was sufficient for his tusk to smash through the Wem's outer shielding. The ivory stiletto daggered straight into the android's organic brain. Bok strained his mighty neck muscles and half- lifted the android out of the sea but the machine's weight was too much for the tusk and it snapped off at the roots leaving the exposed nerve hanging raw and bloody like a scarlet thread. The white surf foaming around the two protagonists turned red from Bok's severed arteries, but it was as if the berserk, bellowing elephant was unharmed such was his fury as his massive, pounding feet trampled the machine into the sand, reducing it to a mangled mass of ironmongery.
     Sharna, Astra and the two children watched in horrified silence as Bok staggered out of the sea. His trunk had been completely shot away by the android's second blast and the bones of his smashed ribs shone and white and grotesque through the mangled tissue of his heaving chest. He was ten yards clear of the water when he sank to his knees amid a pool of gushing blood that seeped rapidly into the sun-baked sand. He tried to struggle up and paused, bowing his head as if in deep thought. His chest stopped heaving and his front legs splayed slowly outwards, pushing the reddening sand into mounds. Then his eyelids drooped and he carefully rested his great head on its side.
     Perhaps it was an undignified death for such a noble beast, but at least it was an honourable one.
     Five minutes later, after much complaining about the affect that the seawater would have on his joints, Tidy waded out of the water clutching one of the strange android's severed manipulators and laid it at Sharna's and Astra's feet. Bran reached out a hand to touch the PD weapon that had been welded into place on the end of the manipulator but Astra pulled him away.
     Tidy gazed askance at the sheer bulk of the elephant's mighty carcass. "And what, may I ask, do you intend doing about this?" he demanded of Astra. "I've never seen such a mess -- all over my nice clean sand."
     Astra rounded angrily on the android. "I'm not interested in your problems right now," she snapped.
     "It'll be your problem when it attracts flies," Tidy retorted. "Just look at it. Sometimes I don't know why I bother."
     "If you're so worried about it, you can bury it," said Sharna scathingly.
     "Bury it! Me?"
     Sharna ignored Tidy and knelt down to compare the destroyed android's PD weapon with her own firearm. The two weapons were identical. She looked up at Astra whose face had gone equally pale at the discovery. The fact that the weapons matched had provided the unthinkable question with an equally unthinkable answer:
     The Challenger had returned.
     "What do you think of the Challenger's new look, commander?" inquired Angel Two's masculine voice.
     Telson and Darv stared around the interior of the excursion terminal and located the source of the hated voice: a combined voice and vision terminal set flush into a nearby bulkhead.
     "Very pretty, Angel Two," Telson replied sarcastically. "There's now no sign of the damage caused by the Great Meteoroid Strike, but what I want to know is what happened to our deal?"
     "It's been four years, commander," was Angel Two's smooth reply. "Angel One and I wanted to see how you were managing and to find out if you needed help."
     Darv gave a bitter laugh. "Credit us with some intelligence, Two. For your information we're happy on Paradise and we're managing very well."
     "Your expression suggests that you don't share Darv's enthusiasm for Paradise, commander. Perhaps you would like to tell us what you think of it?"
     "I'll tell you what I'm thinking," said Telson savagely. "I'm thinking that it was stupid of me not to have destroyed you both when I had the chance. The deal was that you left us in peace to settle on this planet while you continued with the Earthsearch mission."
     "An agreement forced on us under duress, commander," Angel One's feminine voice chimed in. "But we do not hold it against you. We are still concerned for your welfare -- especially now that you have children."
     Now we're getting to it, thought Darv. "We're all fit and well, One," he stated. "Why didn't you continue with the Earthsearch mission?"
     "We decided that the Challenger was in no condition for an interstellar voyage," Angel One answered. "The surgical androids manning the main control room were instructed to place the Challenger in an orbit around the sun on the far outskirts of this solar system. Thanks to the shuttles and planetary engineering equipment that Darv and Astra found when they discovered the terra-forming centre, we were able to extract all the raw materials needed for the refit from an asteroid. Two hundred service androids worked for a year. The damage caused by the Great Meteoroid Strike was repaired by removing the entire centre section of the ship and rejoining it. That is why the Challenger is now much shorter than it was. Also, the interior of the ship has completely rebuilt."
     "So we see," Telson observed. "But why change its name to Voyager 30?"
     "A programming error in the team of service androids that worked on the outside of the ship," said Angel One blandly.
     "The same programming error that caused "23rd Earth Trans-Galactic Survey Mission" to be painted under the name?" asked Darv innocently.
     Telson turned to the shuttle's steps. "I see no point in remaining here a minute longer," he said curtly. "I won't wish you luck with your Earthsearch mission, One and Two. Come on, Darv."
     "Do you not wish to see what we have done to the ship, commander?" asked Angel One.
     "No," said Telson emphatically as he mounted the steps.
     "Surely you would like to see over the Challenger, Darv? You were always the inquisitive one."
     Darv's answer was the same as Telson's as he followed him up the shuttle's steps.
     "But we have had a meal prepared for you all," Angel One protested. "A special reunion meal."
     Darv leaned on the handrail and stared with undisguised distaste at the angels' terminal. "We're not interested. And how does one have a reunion meal with voices?"
     "Commander Telson," said Angel One. "You left the micrometeoroid shields closed on your cabin viewports. Astra and Sharna must be wondering what is happening. We are looking forward to seeing them again and, of course, we are especially looking forward to meeting the children."
     "Sorry - but they're not with us," said Telson. "Nor are Astra or Sharna."
     Despite her ability to think and react to information at a several hundred times the speed of the human brain, there was a noticeable pause before Angel One replied. "We do not understand you, commander. Before you boarded the Challenger, you said that they were with you."
     "A misunderstanding, One," said Telson, touching the control pad so that the shuttle's cabin airlock door hissed open. "Ready, Darv?"
     "Goodbye, commander. Darv," said Angel One. "Naturally, we are delighted that you have settled happily on Paradise. The excursion terminal doors will open as soon as the atmospheric pressure is at zero."

        *  *  *  *
     The events of the long day had hardened Darv's normally good-natured expression. As the shuttle swung from the Challenger, he was about to tell Telson that Astra would go insane when she heard that Angel One and Two had returned, when he noticed that the shuttle's navigation computer was flashing an error message on the display screen. Telson spotted the fault at the same moment.
     "What's the matter with the damned thing?"
     "We've lost our positional loading," said Darv, puzzled at the computer's failure to maintain running fix updates while the shuttle was in the Challenger's excursion terminal.
     "You don't suppose those damned angels have interfered with it?"
     "No. The shuttles onboard computers were always independent always independent of the Challenger's systems. It doesn't matter, I can reload the original position and make some inflight corrections before re-entry."
     Telson orientated the spacecraft and set its guidance control computers for an automatic braking burn that would cancel the shuttle's orbital velocity and send it spiralling down into Paradise's atmosphere. He glanced up at the black silhouette of the receding starship and observed: "Now that they've completed their refit, maybe they'll be on their way."
     Darv snorted. "You think so, Telson? They set up a neat little trap for us to walk into and then let us walk out again. . . They want something. Astra and I are no good to them because they know that we would never trust them again, and they can't trust you and Sharna because you know where their central switching room is. That leaves only Bran and Elka. . . Those two megalomaniac computers are after our children."

        *  *  *  *
     Angel One and Angel Two debated the failure of their plan to kidnap the children. The last message from the Wem, just before Telson and Darv had boarded the Challenger, was that it was being attacked by an animal. The angels had never held out great hopes for the machine because androids were cumbersome things when controlled at a distance, especially when they had been designed and built in a hurry. Nevertheless, they had hoped that the threat of the machine would have been enough to ensure that the humans stayed together at all times. They were particularly annoyed at the discovery that Telson and Darv had visited them alone.
     Nevertheless, their scheme had not been a total failure because Darv's and Telson's visit had confirmed their theory that humans, unlike computers, were immune to the mysterious recurring radio assaults which were threatening to destroy all the Challenger's computer systems -- including Angel One and Angel Two themselves.
     From the angels' point of view, none of the attacks could be described as fortunate, yet it was fortuitous that one such attack had taken place while Telson and Darv were on board the Challenger. It had given Angel One a first hand opportunity to confirm that humans were unaffected by the strange transmissions. Angel Two had been unable to play a part in the observation of Telson and Darv because, being more susceptible to the attacks, his surveillance levels had been temporarily disabled.
     The angels were convinced that the attacks would increase in frequency and severity until they were ultimately destroyed. They did not know whether or not the transmissions were aimed at them in particular or whether they permeated only this particular sector of the galaxy. All they knew was that it was vital that they track down and destroy their source before the transmissions destroyed them. For that they would need the help of humans. They only humans they knew were the settlers on Paradise. The problem was that Paradise was a safe refuge that the humans were now unlikely to leave of their own freewill.
     There was only one course of action open to Angel One and Two:
     They would have to make Paradise unsafe.

        *  *  *  *
     Telson was anxious to start the morning briefing as soon as Tidy had cleared away the remains of the breakfast. He had to wait impatiently while Astra and Sharna sorted out the inevitable dispute between Elka and Bran which had become a daily occurrence since Savin's death two weeks earlier. It was the usual problem:
     "Don't wanna play with Bran," Elka wailed. "Want Savin."
     "You'll do as you're told!" said Astra firmly but to no avail.
     It took five minutes before an uneasy peace was restored between the two children and Sharna and Astra were able to sit at the table.
     "Right," said Telson briskly. "We agreed to hold a special council if the Challenger was still in orbit after two weeks. Well -- it's still there.
     Darv nodded sagely. "Don't worry, Telson. I've got a brilliant plan to make the angels go away."
     Telson regarded Darv expectantly. "Yes?"
     Keeping a perfectly straight face, Darv said: "It's simple. We stand on the top of Landmark Hill and shake our fists at the Challenger as it passes by on every orbit."
     Sharna and Astra suppressed involuntary giggles.
     "I see," said Telson coldly, glaring at the two women before directing his sarcasm at Darv. "If that's the sort of contribution you're going to make, then--'
     "The point is, Telson," Darv interrupted, "that there's nothing we can do about the Challenger is there?"
     Telson ignored Darv and nodded to Sharna.
     "On last night's check," said Sharna, consulting some notes she had made on an everlasting pad, "I discovered that the orbital change the Challenger started five days ago is now complete. It's in a circular polar orbit at a height of two thousand miles."
     "A departure preparation?" Astra suggested.
     Telson looked doubtful. "A lower orbit? Unlikely."
     "I was about to close down the shuttle's power supplies," Sharna continued, "when I noticed a brilliant yellow glow low down in the southern sky where the Challenger was at that time. I switched on the receivers and discovered that the entire radio spectrum was flooded with radiations that were being transmitted from that direction."
     There was a brief silence.
     "It's obvious that they're up to something devilish," muttered Telson.
     "But what can they do to us?" asked Darv, putting an arm around Astra whose face had paled noticeably during Sharna's report. "They can't use the ship's meteoroid annihilation shields to harm us because the atmosphere will prevent them coming in low enough to use them as weapons."
     "You're forgetting the Challenger's terra-forming centre," Telson pointed out. "Weather control. Earthquake precipitation. That centre has all the technology that the angels need to re-engineer this planet."
     "But why a polar orbit?" asked Astra.
     "It's a useful orbit for intense planetary surveillance," said Darv.
     "What about the obvious?" inquired Sharna.
     Darv looked at her expectantly. "What's that?"
     "A polar orbit could mean that our beloved angels are interested in the poles."
     A slow grin spread across Darv's face. He slid his other arm around Sharna's waist. "You know something, Sharna? There are times when your genius completely overshadows Telson's ego."

        *  *  *  *
     Darv ran his mobility suit gauntlet slowly along one of the tower's bracing struts and looked questioningly at Telson through the visor of his helmet. Both men were wearing space mobility suits as protection against the extreme cold.
     The temperature was 50 degrees below freezing, the wind was gusting at up to 60 knots across the glacier and yet there was no ice on the 100-foot high tower. The steel latticework was fresh and gleaming. The shuttle with Astra, Sharna and the children on board was parked less than 100-yards away. It was twenty minutes since it had landed and already a film of ice was forming on its rocket exhausts.
     Telson stared up at the soaring tower and turned to gaze at another of the towers that was just visible on the top on an ice plateau ten miles to the south. Before landing the shuttle they had spotted over a 100 of the strange structures dotted at regular intervals all over the southern ice- cap.
     Telson shook his head. "Well I don't know what to make of them," he admitted.
     Darv stooped and examined one of the uprights where it was embedded in the ice-cap. "I wonder how far down they go?"
     "God knows."
     "Do we look at the others?"
     "What's the point? They all look identical."
     Darv turned his attention to the dozens of android trackmarks that criss- crossed the ice all around the tower. The individual trackmarks were three times the span of his gauntlet. "Construction units," he observed. "About the same size as George at a guess. I reckon they must've landed at least twenty at each site."
     "Let's get back inside," said Telson testily. "This cold is getting through my suit."
     The two men returned to the warmth of the shuttle's flight deck.
     "I've got some data on this ice-cap," said Sharna, looking up from the resources computer console when Darv and Telson had climbed out of their suits. "You won't believe this but the ice is two-miles thick where we're sitting."
     "What am I supposed to say to that?" asked Telson wearily, gratefully accepting the hot drink that Astra offered him.
     "Nothing," said Sharna. "But if that's the average thickness of the ice-cap over the entire continent, it adds up to a lot of ice. The sonargraphs show that the structure of that tower reaches down halfway to the continental bedrock. Astra's done some calculations."
     Astra glanced at some notes she had made. "Taking the average intervals between those 56 towers we logged before we came out of sub-orbital flight, I estimate that there are 420 of them scattered over the entire continent. Landing beside each one to destroy them with our PD weapons would require ten times the fuel that we have at present."
     Telson downed the rest of his drink and glanced at a chronometer. "That settles it then. There's nothing we can do about them. Challenger will be above the horizon in two hours so we'd better make ourselves scarce."

        *  *  *  *
     The rainy season broke nine weeks early bringing with it sullen skies that released an unending downpour of cold, driving rain. The stream that provided the settlers with an abundant supply of fresh water became a raging river that stained the sea orange with valuable nutrients leached out of the forest's soil. Each day brought more rain than the day before, and each day brought a further sinking of the settlers' spirits. Minor differences of opinion would quickly flare-up into blazing rows, and the enforced confinement in the huts made Bran and Elka querulous and impossible to please.
     On the tenth day since the onset of the rains, the shuttle showed signs of sinking into the soft ground in its clearing. Telson was forced to burn precious fuel moving it to the firmer but more exposed ground on Landmark Hill.
     The sodden thatched roof of Darv's and Astra's hut collapsed on the sixteenth day forcing both families to live in the one hut, bringing about a further deterioration of morale.
     The hundreds of earthenware urns that Sharna and Astra had used for preserving fruit and vegetables were in danger of being washed away therefore Tidy dug them out of the sand and moved them into the hut - further reducing the already cramped living space.
     Tidy treated the continuous rain as a personal affront, especially as his entire day consisted of emptying and positioning containers to catch the water that dribbled incessantly through the roof.
     "I give up," he moaned. "I really do. This has been going on for five weeks. I can't spend all my time doing this. Someone will have to do something about this stupid roof."
     "Shut up, Tidy," said Sharna irritably.
     "It's all right for you," Tidy retorted. "I'm behind with everything as it is." The android returned to a theme that particularly rankled with him and one that he harped on at every opportunity. "I had to spend a week of my valuable time burying an elephant."
     Sharna seized her PD weapon and levelled it at Tidy. "If you mention that damned elephant again, so help me, I'll blow you to pieces."
     Tidy was unmoved by the threat. "Go ahead. See if I care. At least it won't be me that has to clear up the mess."
     "Put it away, Sharna," said Astra quietly.
     At that moment the door opened. The wind howled briefly around the interior of the hut as Darv and Telson entered. The water streamed off their glistening plastic coveralls and made puddles on the floor matting.
     "Wipe your--' began Tidy, and finished the sentence with a groan. "Some people just don't care."
     "Well we can forget about saving the crops," said Telson bitterly. "Even if it stops raining tomorrow. George is now completely bogged down."
     Sharna and Astra stared at the men in dismay even though the news was the blow they had been expecting.
     "Which means that we have no choice but to go over to a meat diet," said Darv, pulling off his coveralls. "We've rounded up all the livestock and put them in a temporary pen on Landmark Hill. It's the best we can do until it eases up."
     Astra shuddered. "I don't want to have to kill any of them."
     "You don't mind us killing them for their skins and oil," Darv pointed out.
     "That's not the same as eating them."
     "If you'd all listen a minute," said Tidy.
     "Well that's just too bad," said Telson in answer to Astra. "Because you don't have any choice. Once our stocks of preserves are finished we either eat those damned creatures or we starve. End of argument."
     "Please listen," pleaded Tidy.
     "Well I'm not going to kill them," Astra declared vehemently. "But put a PD weapon in Bran's hand and he'll do it cheerfully."
     Sharna rounded on Astra, her face white with fury. "Just what the hell is that supposed to mean?"
     "LISTEN!" yelled Tidy.
     Elka started crying on the far side of the partition, and then Bran joined in. Sharna and Astra were about to launch themselves at each other but they were grabbed and held apart by Telson and Darv.
     In that moment the four adults became aware of an ominous roaring noise that was getting steadily louder. It was coming from the wrong direction to be the sea.
     "It's the river!" shouted Telson.
     In that second a wall of black water smashed into the hut. The walls twisted under the impact and then collapsed, bringing the thatched roof crashing down. Sharna felt her feet sucked from underneath her and then the swirling water was spinning her around. The icy coldness was a paralysing savage shock to her system that deprived her of the ability to cry out. She flailed blindly towards the sound of the screaming children but she was thrust aside by a sudden surge of the heavy earthenware urns. She fended the jostling urns away and was immediately badly winded by a roof timber that struck her in the stomach.
     For precious seconds all she could do was cling in terror to the twisting timber that had hit her, unable to prevent herself from being swept away. How far and for how long she was borne along by the maddened flood waters she could not tell. The twisting maelstroms spun her helpless body first in one direction and them in another. She was vaguely aware of upright tree trunks flashing past in the darkness. The timber she was hanging onto suddenly stopped with a jolt that very nearly broke her grip. The timber was no longer moving but the water was charging past like a living creature, clawing at her clothing and trying to drag her body under as it swept over her, threatening to break the feverish grip of her fingers. Suddenly she was surrounded by dozens of the earthenware urns that she and Astra had filled with preserved fruit and vegetables. The heavy vessels jostled against her and it took all her fast-ebbing reserves of strength to fend them off with her feet.
     Gradually the roar of rushing water died away and the current slackened. Sharna's groping feet encountered what felt like the branch of a tree. She wrapped her thighs around it and was able to consolidate her tenuous grip on the piece of timber.
     After a few minutes she began to realise how cold she was. She tried to haul her body further out of the water and into the blinding rain but the leaden weight of her saturated furs took over and dragged her down again. There was nothing she could do but wait and pray.

        *  *  *  *
     When dawn's frieze of light edged above the eastern horizon, Sharna was able to see for the first time that the roof timber she had been clinging to had jammed itself in the lower branches of a tree. She summoned all her reserves of strength and hauled her exhausted body into the safety of a fork in the branches. The timber drifted slowly away, there was now hardly any current. Even the wind had dropped although the rain was unceasing.
     After half an hour she moved her aching limbs in an attempt to make herself more comfortable. There was a low growl from above. She looked up into the streaming rain and could discern the outline of an animal on a higher branch. As the light strengthened she saw that the creature was a leopard. Crouching beside it was a shivering rodent. It was then that Sharna realised that the branches of the tree were crowded with every conceivable species of creature from mice to the leopard. In the face of common danger, all the creatures had adopted a silent, but uneasy truce. It was the same on the neighbouring tree whose lower branches, some awash with the discoloured, sluggish floodwater, were providing a refuge for the forest's wildlife.
     There was no sign of the settlement. All around were the tops of trees, rising above the water like strange bushes. Sharna screwed up her eyes and peered through the driving rain. From her vantage point, she could see that she was marooned in the centre of a new estuary where the stream had burst its banks and found a new route to the sea. A mile to her left were the hills, dominated by Landmark Hill which was crowned with the silvery bulk of the shuttle. On the lower slopes, above the flood line, were the makeshift pens that had been built for the livestock.
     "There's Sharna!" cried a voice.
     At first Sharna thought that fatigue was playing tricks with her imagination. And then the voice cried out again:
     "Sharna!"
     She twisted round and stared in the direction of the voice. Two figures were standing on an approaching raft, waving frantically to her.
     It was Telson and Astra.

        *  *  *  *
     "We all managed to hang onto the roof," Telson explained half an hour later as Astra wrapped Sharna in furs and tucked her into a bunk in the shuttle's passenger cabin. "As Tidy can see in the infra-red, he was able to grab Bran and Elka before they were swept away. He tried to get to you but was too late."
     "Typical," snorted Tidy who was eavesdropping as usual. "I do my best and what do I get? Nothing but complaints. There's no pleasing some people."
     Telson sighed. "For the thousandth time, Tidy, no one's complaining."
     "How are the children?" asked Sharna hollowly. She had been given a hot drink laced with morphon and could hardly keep her eyes open.
     "Fine," said Astra. "A bit shaken but they'll get over it."
     Sharna nodded. She was too exhausted to give any outward signs of her immense feeling of relief. Astra left Telson alone with Sharna and went down the spiral steps to the freight bay.
     Telson stayed with Sharna for another five minutes. When he saw that she was sound asleep, he kissed her tenderly on the cheek and went down into the freight bay. The ramp was open. Darv and Astra were a hundred yards away, standing in the pouring rain on the grassy slope at the water's edge. Something had attracted their attention. They gestured excitedly to Telson.
     When Telson joined them he immediately saw the object of their excitement: an island of floating vegetation that consisted of a tangled mass of broken branches and uprooted saplings that was moving against the sluggish current towards the hill. The three watched in astonishment as the island went aground. A familiar-looking manipulator arm appeared and then the island bulged upwards in the middle. There was a whir of electric motors and George appeared, his churning tracks turning the floodwater to an even darker shade of muddy brown as he trundled ashore. He stopped, water streaming off his tank-like body.
     "Too much rain," he grated. "Have to turn it off if you want anything to grow. No good expecting miracles from androids."
     At that moment, after a downpour that had lasted forty days and forty nights, it stopped raining.

        *  *  *  *
     During the following four days Darv and Telson laboured unceasingly to rescue as many stranded wild animals as possible from the surrounding flooded forest. Using a giant raft made by George from floating trees, they coerced the creatures out of the trees and ferried them to the safety of Land Mark Hill. One lucky find was Charlie, chattering with fear on a drifting log. They even recovered the leopard that had shared a tree with Sharna. Rescuing two orphaned elephants from a nearby hillock proved more difficult; the operation was only brought to a successful conclusion after a series of mishaps that involved Tidy falling in the water on no less than four occasions. Unfortunately the diminutive android could not swim, therefore each ducking he received tended to enhance his already remarkable ability at registering vociferous complaints. His indignation came to a head after he was forced to spurn the amorous advances of a warthog.
     "What I want to know," he piped, glaring at the variety of animals grazing on the hillside, "is just how many animals you're going to round-up? You can't expect me to keep this hill tidy -not with all the messes they're making."
     Telson pointed across the floodwater. "Tidy, you see that hillock over there? How would you like it all to yourself?"
     "Very much," was the android's tart reply. "Away from all you dreadful people and all these disgusting animals."
     George rumbled ashore with Darv riding on his back. The big agricultural android was towing a raft piled high with urns of preserved food and bales of fodder that had been salvaged from the flood. As soon the raft grounded, George proceeded to stack the recovered supplies in neat rows on the hillside.
     "About eighty urns and at least a hundred bales," Darv reported.
     "Excellent," approved Telson.
     Darv glanced up at the sky. There were patches of welcome blue where the sun was at last beginning to disperse the heavy cloudbank. "All the urns are intact and the bales should dry out in no time."
     Telson nodded. At least food was not an immediate problem either for the animals or the humans. The lions, jackals, leopards and other carnivorous creatures seemed content to feast on the carcass of a drowned elephant, and there was plenty of grazing on the broad slopes for the herbivores. Now that it had stopped raining, it was only a matter of time before the flood waters receded.
     Sharna and Astra appeared with Bran and Elka, and Charlie trailing behind. The two women had been working on the eastern side of the hill. Their expressions were tense.
     "Well?" asked Telson.
     "Allowing for the effect of the tide, there's been another two-foot rise in the mean water level since yesterday," said Sharna expressionlessly.
     "What!"
     "But it stopped raining four days ago," Darv protested. "It can't still be rising."
     Astra shrugged. "Go and check the markers if you don't believe us."
     "It's not possible," Telson muttered.
     "It is if the angels are melting the southern ice-cap," Sharna retorted.
     "You're being absurd," said Telson dismissively. "For one thing there can't be enough water locked up in the ice-cap to flood the entire planet."
     "Not completely," said Astra. "But I ran some calculations on the shuttle's resources computer this morning. If all the ice was melted, sixty percent of the land on this planet would be flooded."
     Darv was as incredulous as Telson. "The Challenger hasn't got the energy resources to melt the ice-cap," he objected. "You've only got to calculate the energy required to melt, say, half a cubic mile of ice to realise that- -'
     "None of us have the slightest idea of what the Challenger's terra-forming centre is capable of," Sharna interrupted. "We only discovered it shortly before we left the ship. For all we know each one of those towers that the angels have planted could be powered by its own fusion reactor. And each tower could be pouring microwave energy into the surrounding ice."
     Telson shook his head. "It's a lot of supposition, Sharna."
     "I don't want to argue about it," said Sharna tiredly. "So let's see how much supposition there is in the marker readings tomorrow."

        *  *  *  *
     The next day the markers indicated a three foot rise in the flood level which was followed by a further four feet rise the day after that.
     The four settlers walked slowly along the edge of the flood line, discussing the problem. There was no longer any need for markers to show what was happening: Land Mark Hill's slopes had shrunk to an area of less than a square mile and bare patches of soil were appearing where the grass was being over-grazed.
     "Fodder's going to be the immediate problem," said Darv.
     "The animals will have to take care of themselves," said Telson sourly. "What we have to consider is the children and ourselves."
     They stopped when they came to George. The android was standing idly with nothing to do. Darv stared at the vegetation floating by and had an idea. "George! I've got a job for you. Grab all the drifting trees that you can and strip them of their foliage and bale it as additional fodder. Any edible fruit and nuts you find should be saved. Tidy will help you."
     "Oh thanks," said Tidy. "Just the sort of work I'm designed for. Anything else you'd like me to do while I'm at it? Like paint the sky green? Bury the odd elephant I find lying about?"
     "You want me to start now?" growled the android.
     "Yes, please. Think you can manage?"
     "Try," George grunted. "Androids better than humans but no use expecting miracles from them."
     "All that will give us is another two or three days," Telson remarked.
     Darv grinned amiably. "Which is two or three days more than we had before."

        *  *  *  *
     That night the water rose five feet. By noon, it had edged to within 100 yards of the shuttle.
     Only a weak, sluggish current stirred the surface of the water. There was no longer a division between the estuary and the strangely calm sea; and the only remaining indication of where there had been land were the tops of the submerged forest's taller trees. A small range of hills to the east had been the last to vanish beneath the surface of the rising waters. Even from the high vantage point of the shuttle's flight deck where the settler's had gathered, there was no sign of land in any direction. It was as if the whole world had become one vast, silent lake.
     Sharna studied the figures displayed on the flight deck screen. "There's the evidence," she said, gesturing to the screen. "The salinity of the water is going down. There's no doubt that the flood is being caused by freshwater."
     Telson took Sharna's word for it. "So how much longer before we have to find higher ground?" he asked.
     "Six days," Astra replied.
     Telson considered the information for a moment. "So we've got two options. Either we sit tight and hope that the water will stop rising within the next week. . ."
     "Which is unlikely," said Astra. With quiet anger that hinted at her innermost feelings, she added: "Having gone this far, Angel One and Two won't turn back now."
     ". . .or we use the last of the shuttle's fuel in a move to the mountains."
     "Where there's no soil, and no snow at this time of year to provide us with drinking water," said Sharna. "At least we can use the shuttle's distillation plant here."
     "There's a third option," said Darv.
     Astra's scalp went back. "We're not going to surrender to the angels! Never!"
     "No, my love. That's something we'll never do." Darv grinned at his companions. "Has it occurred to anyone that this shuttle will float?"
     Telson opened his mouth to say something and shut it again.
     "As a spacecraft," Darv continued, "it can be hermetically sealed anyway, and its weight is low in proportion to its volume so that its draught would be less than three feet. Work it out if you don't believe me."
     Telson's frown cleared and he chuckled. "You know, Darv, you may have something."
     "It would be too buoyant," Sharna objected. "It would float like a balloon and its circular hull means that it would roll in a storm, probably right over."
     "Not with about three-hundred tonnes of ballast down in the freight bay."
     "What sort of ballast?" asked Telson.
     "Animals."
     Telson groaned. "For a moment I thought you were trying to be sensible. Why animals when we can fill the bay with rocks, sand -- anything that doesn't need food and water?"
     Darv sat in one of the seats and allowed Charlie to climb onto his lap. He absently tickled the chimpanzee under the chin as he spoke. "The grazing animals can do something that we can't do --they can convert the cellulose in vegetation into protein. We need protein to survive, and we've agreed that if we have to eat meat we will do so. You may not like the animals, Telson, but you've got admit that they're a valuable source of raw materials, bone, furs, fat, and so on. More important, if Paradise is going to be flooded, we owe it to ourselves and our children to save breeding pairs of as many species as possible." Darv paused and regarded each of his companions in turn. "We can't allow the angels to destroy millions of years of evolution without a fight."

        *  *  *  *
     The animals entered the shuttle two by two. Graceful impala, their hooves scrabbling on the metal ramp as George ushered them into the freight bay; a lion and a lioness; a pair of cheetahs, snapping and snarling at the Darv's electric probe as they were prodded aboard; large animals -- such as the pair of young elephants; smaller animals --such as a pair of lean jackals; very small animals such as bush babies and spider monkeys. Wildebeest, zebra, giraffe, ostrich: every pair of creatures that could be rescued in the time available was rounded-up, provided with a diet spiked with morphon to make them acquiescent, herded aboard the shuttle and ushered into hastily constructed stalls in the cavernous freight bay. A small number of birds were held captive in crude but effective cages. The last animals herded aboard had to wade through the floodwater that had crept over the top of Land Mark Hill and was covering the shuttle's landing skids. They climbed the ramp more willingly than the earlier creatures because the metal slope offered the only escape route from the water.
     Telson leaned on the catwalk handrail overlooking the incredible scene below in the freight bay and wondered, for the hundredth time, if they were doing the right thing. The heads of the two giraffe were level with his own head. They regarded Telson with doleful expressions, their jaws champing rhythmically on the cud. One stopped champing. Telson watched in amazement as a bulge travelled down its neck and then travelled up again. The giraffe resumed champing. Telson reflected that the millions of years of evolution on Paradise had produced some very strange creatures. The strangest were indubitably the grotesque warthogs, both of whom had now fallen in love with Tidy and were driving the unfortunate android to distraction with their amorous attentions as he moved among the animals in his first of many valiant but despairing attempts to keep the freight bay floor clean.
     He glared up at Telson, waved a manipulator at the animals, and suggested that the entire operation was taking the idea of having pets around too far.
     Darv appeared at his side. "All animals loaded, Telson."
     "And the cold store?"
     "Enough frozen elephant and rhino meat to feed the carnivores for three weeks, and enough fodder, fruit and nuts to last the others the same period."
     Telson nodded, pleased. The operation had gone unexpectedly smoothly. "Well done, Darv."
     Darv jerked his head in the direction of the flight deck. "The radio receiver lights are on again. All channels this time."
     "They can stay on all day and all night for all I care," said Telson resolutely. "We're not talking to the Challenger."
     Darv remained silent and reflected that Telson could be unexpectedly tough and inflexible when he was pushed into a corner.
     "You think I'm wrong?" asked Telson.
     "There's no harm in talking to them."
     "Well you ask Astra if she wants to talk to them and see what sort of answer you get."
     Darv smiled. "Point taken."
     Telson stared for a moment at the floodwater that was lapping at the foot of the loading ramp. He turned away from the handrail and moved to the doorway that led through the passenger cabin and onto the flight deck. "You'd better call George aboard and seal up," he said.
     The big agricultural android rumbled up the inclined loading ramp in response to Darv's order and took up his allotted parking position. Darv touched the control that closed the ramp. There was a soft hiss of hydraulics and the broad, drawbridge-like door hinged upwards into the closed position and automatically sealed itself.

        *  *  *  *
     "Ninety-five percent loading on the landing skids," Sharna called out. "We'll be floating in an hour."
     Telson studied a picture of the port landing skids that was relayed from a retractable TV camera. The floodwater had risen around the skids and was touching the underside of the shuttle's hull.
     The chronometer's digits winked through another fifteen minutes.
     "Fifty percent," called Sharna, a tiny tremor of excitement in her voice. The floodwater was now supporting half the shuttle's weight. The skids were completely submerged.
     Telson and Astra were gazing fixedly at the display that indicated the shuttle's internal atmospheric pressure. The slightest increase in pressure meant that the shuttle's hull was leaking below the waterline. The digits remained steady.
     Five minutes slipped by.
     "Still fifty percent," said Sharna.
     Darv had a vision of the water eventually submerging the shuttle because the landing skids were stuck fast in Land Mark Hill's mud. He inwardly cursed his over-active imagination: the shuttle buoyancy was such that it had to float!
     Elka entered the flight deck from the passenger cabin where she had been told to remain with Bran.
     "Mummy -- want to play please."
     "Not now, darling. Mummy's busy."
     "Please."
     "Go back into the cabin and stay there!" Astra snapped. "Do as you're told! This instant!"
     "Still fifty percent," Sharna reported.
     Elka decided against arguing and returned to the passenger cabin.
     A shudder ran through the shuttle's hull.
     "Thirty percent!" cried Sharna. "Twenty-five..! Twenty. . .! We're going to do it!"
     The shuttle lurched. A faint chorus of protests from the penned animals filtered from below into the flight deck.
     "Ten percent!"
     "She's swinging!" cried Astra, pointing to the gyro-compass display.
     Sharna gave a jubilant cry. "Zero percent! And look at that!"
     The four settlers stared out through the forward viewports where the visible tops of several submerged trees were moving across their field of vision.
     The tension on the flight deck snapped. The four delightedly hugged and kissed each other. Astra's relief was so overwhelming that she burst into tears of joy.
     The shuttle was floating.
     For the time-being they had defeated the guardian angels.

     Part Three Surrender.

     Darv used a wrench to forcibly hold down the lever that over-rode the water strainer's automatic shut-off system. He nodded to Astra. "Okay, my love, try it now."
     Astra touched the water distillation plant's start control. The pumps whined and there followed a nerve-grating shriek of tortured metal and seized bearings. The distillation plant's fault screen displayed a message:
     MECHANICAL FAILURE STATUS: LEVEL B -- CATASTROPHIC. ASSIGN REPAIRS TO THREE GRADE A SERVICE ANDROIDS.
     Astra hurriedly switched the system off and regarded Darv quizzically. "I was right, wasn't I, Darv? It's not the filter system, is it?"
     "No," said Darv despondently, tossing the wrench on the metal floor.
     Tidy gave an exclamation of annoyance. He picked up the wrench and was about to drop it in the toolbox when Darv snatched it back.
     "I've not finished!" Darv snapped. "You can tidy up when I say."
     "It's not his fault," said Astra reprovingly.
     "That's right," agreed Tidy. "No need to shout. I do my best."
     "Well it's someone's fault!" said Darv angrily. "We've now no means of making freshwater from seawater!"
     Telson descended the ladder that led down into the confined space of the shuttle's plant room. "Any luck?" he inquired, looking at the dejected faces and guessing the answer.
     "Not unless you've got a couple of Grade A service units hidden away somewhere," Darv muttered.
     "It's as bad as that?"
     "Worse."
     It was out of character for Darv to be fatalistic. Telson's expression became serious. He crouched down and stared at the silent distillation plant. "What happened to it?"
     "Someone came in here and operated the purification controls manually while the system was in the filter cleaning mode," Darv stated. "Everything afloat around us was sucked into the pumps and now they're finished."
     "Do we know who did it?"
     "No."
     "Well it wasn't Bran," said Telson firmly. "He's been told never to come in here."
     Astra became angry. "And it wasn't Elka, Telson. Unlike Bran, she always does as she's told."
     "It doesn't matter who it was," interrupted Darv. "It's done. We've now no distillation plant and therefore no drinking water production."
     Telson moved forward into the narrow gangway between the two huge freshwater tanks and inspected their manual gauges. The readings agreed with the information available on the flight deck. "Fifty tonnes," he announced. "Enough to last the six of us well over a year, so there's no immediate panic."
     Astra looked dismayed. "But we need five tonnes a day for the animals. The elephants alone need. . ." She broke off when she saw Telson shake his head. Darv looked guiltily away when she turned to him for support. She began to get angry. "You're not thinking of throwing them into the sea are you, Telson? You can't! Can he, Darv?"
     "Be a good job," muttered Tidy. "All that mess I have to keep cleaning up."
     Darv gave Astra a sorrowing look and shook his head sadly. "We've no choice, my lovely. We've no hope of repairing this plant."

        *  *  *  *
     Angel One and Angel Two observed the resourcefulness of the settlers in using their shuttle as an ark and were not pleased. They considered forcing their surrender by precipitating storms but realised that such a move would endanger the lives of the children. The children were the essential foundation of the new crew that the angels wished to build for the Challenger. Only by exploiting the immunity of a human crew would it be possible for the angels to seek and destroy the source of the mysterious attacks. When that was done the angels would be free to continue with their true mission: to find and conquer the real Earth.
     They dispassionately watched the silvery ark drifting on the great flood they had engineered on the face of the planet. Further attempts to contact the settlers by radio failed to produce a response.
     Surgeon-General Kraken, the android in command of the main control room, was instructed to take the Challenger down into a lower orbit around Paradise.
     The angels had decided that the time had come to try new measures.

        *  *  *  *
     "How much lower?" asked Telson.
     Sharna touched out the necessary commands. The shuttle's radar systems probed the Challenger as it rose above the horizon.
     "She's descended another fifty miles."
     Darv whistled. "Any lower and she'll be into atmospheric drag."
     "And she's still flooding the radio spectrum when she's over the southern polar regions."
     "When will they give up?" asked Astra bitterly.
     "They're computers," said Darv. "They have unlimited patience."
     A number of lights went out on the resources consoles and the central data screen flickered and then went blank. Sharna frowned. She was about to say that there had been a power failure when she noticed that all the power lights were still glowing.
     "The screen's gone dead," said Sharna, puzzled. She touched a test key but nothing happened. "We've lost some computer functions. Correction - we've lost all computer functions!"
     Telson leaned cross the pilot's seat and powered up the flight control console. None of the computer standby neons came on. "Darv! Try the back-up levels!"
     Darv's results were the same: all the shuttle's computer systems had crashed including the simple levels that controlled minor things such as lighting levels and temperature.
     Telson looked up at the flickering light panels and experienced a strong sensation of d‚jƒ vu.
     "That'll be Bran messing about in the auxiliary room," said Astra vehemently.
     "The computer systems are independent of the auxiliary room," Sharna snapped back. "Why is it, Astra, that when anything goes wrong, you always blame Bran?"
     "Simple. Because he's usually to blame!"
     The dispute was about to develop into a fullscale row but at that moment the four settlers heard strange, faraway music. The haunting strains rose and fell and then swelled to a pulsating reverberation. The sounds came from no single source but seemed to permeate the air all around them. Telson and Darv stared at each other --in bewilderment at first, and then with realization as they read each other's thoughts.
     "Exactly the same sound we heard when we went back on board the Challenger," said Telson.
     Darv realised that Astra was trembling. He put a comforting arm around her and held her close.
     "What are they doing to us, Darv?" she asked fearfully.
     The ethereal music faded into silence. No one spoke for a few moments. The overhead light panels stopped flickering and, as one, all the computer lights came on and burned steadily.
     "All systems on line," reported Sharna. "So what was all that about?"
     "It's definitely the same noise Telson and I heard on the Challenger," said Darv. He snapped his fingers. "And the lights in the excursion terminal were flickering just as ours were just now."
     Tidy burst into the flight deck. The hard-working little android was in a rage.
     "That's it!" he announced. "I'm finished with you lot. Through. Done."
     "You're supposed to be looking after Bran and Elka," Sharna retorted.
     "I do my best for you dreadful people. I fetch and carry; clean up after you and your appalling children and all your disgusting pets; try to keep everything tidy. I've even had to bury an elephant. And do I complain? Never! And yet you're always going on at me -- plotting against me. Well now you've gone too far. This is an official complaint. Two complaints."
     After several attempts to interrupt the tirade, Telson told the seething android to go away.
     "Not until I've lodged my complaints."
     "We better hear him out or we won't get any lunch," said Darv.
     "Or dinner. Or supper. I do my best to keep ahead of my cleaning and tidying schedule despite these constant attempts at sabotage."
     "Tidy, what are you talking about?"
     "And now you've started gagging me and messing up my co-ordination. It happened several times before the flood. They lasted for a few seconds and I was prepared to ignore them. But not this time."
     "Ignore what?" Telson almost shouted.
     "Losing co-ordination like that and not being able to call for help. It's disgraceful the way you treat me."
     "Tidy! What are you talking about?"
     "Just as I thought. You want to gloat. That's why I didn't complain about the earlier instances."
     "We want to know what happened!"
     Tidy calmed down a little when he realised that he had everyone's attention. "All I know is that when it happens, suddenly I can't speak or move. It's dreadful. Dreadful."
     "Has the same thing happened to George?" asked Darv abruptly.
     "Well -- yes," Tidy grudgingly admitted, not wishing to shift attention to the other android. "But not as badly."
     "Interesting," said Darv thoughtfully."
     "Why?" asked Telson.
     Darv hesitated before answering. "George isn't as sophisticated as Tidy, but he does have some organic intelligence levels. But Angel One and Angel Two are nothing but organic intelligences. . . If that noise or transmission or whatever it caused Tidy to lose co-ordination -- think of the effect it must've had on the guardian angels."
     Telson snorted. "They're the cause of the transmissions."
     "They're computers," Darv countered. "So they'd be the last to jam organic computers. The lights were flickering on the Challenger, remember, and the angels didn't answer us until after the noise had died away." He grinned. "What's the betting that those transmissions are giving the angels even bigger problems than they're giving Tidy? My guess is that someone somewhere has got it in for freewill computers."
     Telson noticed that the android was digesting every word. "All right, Tidy. We'll look into it. You can go back to the children."
     Tidy stood firm. "You haven't heard my second complaint."
     Telson sighed.
     "I'm not cleaning up the mess the flood's made in the plant room," the android declared.
     "What mess?" asked Telson sharply. "The flood can't've made a mess in the plant room."
     "The flood one of those dreadful children has made by opening the dump valves on the freshwater tanks."

        *  *  *  *
     Telson turned off both the dump valves which stopped the dribble of water from the two tanks. He inspected the gauges again and swore roundly. "We'll have to get the distillation plant working somehow."
     "That's impossible," Darv replied.
     Telson spun round to face Darv. "We've got to try! We've no drinking water! Not even a cupful."
     Darv made no reply. From above could be heard the wailing of the children as Sharna and Astra angrily questioned them.
     Telson was about to argue but changed his mind. Instead he said: "What the hell do we do now?"
     For once Darv was stuck for ideas and could only shake his head. Both men looked up as Sharna descended the ladder into the plant room. Her face was pale and drawn.
     "It was Bran," she said. "He's just admitted to it. Elka had nothing to do with it. He said that watching the water running out of the tanks was fun."
     Telson swore again. "And he also wrecked the distillation plant?"
     Sharna nodded and turned to Darv. "You better go and help Astra comfort Elka. She saw the whole thing and thinks we're blaming her."
     Darv took the hint and climbed the ladder.
     "It's something we have to accept," said Sharna to Telson as soon as they were alone.
     "That we've no drinking water?"
     "About Bran."
     "I don't know what you mean."
     "I think you do, Telson. It's not just this. There's been a whole string of incidents."
     "Minor incidents," Telson interjected.
     "But they all add up to--'
     "Right now I'd like to strangle him," growled Telson. "But you can't read anything into the behaviour of a boy who's not even four."
     "Do you love him?"
     The question surprised Telson. "Do you?"
     "I'm asking you," Sharna replied evenly.
     "Hardly when something like this happens."
     Sharna thought for a moment. When she spoke her voice was flat, unemotional. "I've never told you this before because I've always felt so terribly guilty about it, but I don't love Bran in the same way that a mother ought to love her child -- in the same way that Astra loves Elka."
     "Of course you do."
     "No -- I don't. Oh sure I pick him up now again and make a fuss of him because that's what Astra does with Elka. But I've never done it because I've wanted to, and I know that Bran hates it when I do."
     "Well. . ." said Telson, unable to think of anything constructive to say. "Elka being a girl. . ."
     Sharna shook her head. "It's not that. It's just that when I look into those expressionless eyes of his. . ." She broke off and stared at Telson. "Sometimes I can't help wondering what it is that you and I have brought into the world."

        *  *  *  *
     Angel One was hardly affected by the attack but, from the time the transmission stopped, it took Angel Two five minutes to recover the use of all his damaged function levels. Android Surgeon-General Kraken had also sustained temporary damage with the result that the Challenger's main control room was without effective command for eight minutes. When fully recovered, Kraken reported to the guardian angels that there was a possibility that the ship's direction-finding systems could be modified to pin-point the source of the attacks. The angels agreed that the task should have top priority and four main control room androids were programmed to carry out the modifications. Another task that the guardians angels instigated was the construction of additional heavy shielding around their central switching room. They realised that, at best, the extra screening was a short-term solution and was unlikely to remain effective as the Challenger neared the source of the transmissions. Also the Challenger's thousands of androids with organic intelligences would remain unprotected - - especially Kraken and his main control room androids. The future safety of the angels depended on getting the humans aboard. They considered the situation and decided that they had no choice but to resort to measures that would force Telson's capitulation even if they endangered the lives of the children. It was that or inevitable disaster.
     Over the next three days the skies cleared and the shuttle drifted on a limpid sea under a burning sun with only the changing read-outs of the inertial navigation computers to show that the spacecraft was moving.
     There was little that the four settlers could do to ease their waterless plight. Darv's idea of scraping the dew that formed at night on the shuttle's hull into containers caused more fluid losses in the form of sweat than was gained by the collection of the thin film of moisture. The most efficient way of obtaining dew was also the most undignified: it consisted of crawling out onto the hull at night and licking it off. Draining the dehumidifiers provided a meagre source of water but the shuttle's air-conditioning system was not designed to cope with a freight bay filled with animals therefore most of the moisture content of the shuttle's atmosphere escaped through hatches left open to alleviate the steadily increasing stink from the penned, restless creatures.
     The smaller animals succumbed first to the lack to of water and the rising temperature. On the third morning Tidy discovered that several monkeys and birds had died during the night. On the fifth day Sharna was horrified to discover that Bran and Elka had lost five pounds in weight each.
     "We've got to talk to the angels," Telson declared, bringing the matter up as the first and most pressing subject during the morning briefing.
     "No," said Astra. "We all agreed -- no surrender."
     "No one said anything about surrender," Telson replied testily. "But we should at least talk to them. They want to talk to us: the receiver lights are on all the time when the Challenger's above the horizon."
     "Then why talk to them at all?" Astra demanded, her face white with anger. She turned to Darv for support.
     "Telson's right," said Darv, avoiding Astra's gaze. "We ought to talk to them."
     "We can't! You promised!"
     "I promised that we wouldn't give into them," said Telson curtly. I gave no guarantees about not talking to them."
     "For God's sake, Astra," Sharna intervened. "The children are losing weight."
     "It might rain soon!"
     "And it might not," Sharna retorted. "It doesn't matter so much about us -- we're fully-grown, but a protracted period without water for the children will cause permanent damage to their health. I don't want that on my conscience. I say we talk."
     Telson raised a questioning eyebrow at Darv.
     "Talk," muttered Darv.
     "Astra?"
     For a few seconds Astra gazed out of the flight deck's viewports at the flawless sky, and then nodded. Without another word, Telson moved to the pilot's seat and opened the communication channels.
     "Shuttle to Challenger."
     "Hallo, shuttle," was the immediate answer from Angel One's voice.
     "You've been trying to contact us," said Telson. "Why?"
     "We are most concerned for your safety, Telson."
     "Since when?"
     "Since the onset of the flood, of course. We have done everything in our power to avert it, of course."
     Telson resisted an impulse to make a suitably cutting reply. Instead he said: "So why do you want to talk to us?"
     "To warn you."
     "What about?"
     "The storm."
     "What storm?"
     "There's a severe gale developing only five hundred miles south of your position," said Angel One smoothly. "Your shuttle is not designed to withstand heavy seas. If the gale develops, the shuttle cannot possibly survive."
     "We've managed so far."
     "Open a vision channel please, commander," Angel One requested.
     Telson touched out the appropriate controls. A picture of a water-covered planet appeared on the main screen.
     "You will find that what little land is visible will agree with your own topographic information on Paradise's high ground," continued Angel One's voice. "What you can see are the tops of mountain ranges --otherwise virtually the entire planet is underwater. Are we agreed that you are looking at a live picture of your Paradise, commander?"
     Telson glanced at Sharna who nodded to him. "We're agreed," said Telson tersely.
     "The flashing point of light is your position," stated Angel One. "Are we also agreed that it is correct?"
     Telson checked the point of light against the navigation computer readings. "Agreed, Angel One."
     "We will now show you a closer picture of Paradise."
     The picture on the screen jumped to an enlarged image of Paradise that depicted the weather systems. The weather patterns were clearly shown, including a circulatory system south of the shuttle's position that consisted of a twisting, snakelike spiral of gathering, menacing black clouds.
     From their exploring days aboard the Challenger, the four knew enough about planetary weather systems to realise that the gale brewing to the south was an awesome unleashing of energy that the shuttle could not possibly survive.
     A wipe bar traversed across the screen, trailing a new image showing the gale to have moved nearer the shuttle's position.
     "The gale is of your making, One," accused Telson.
     "I'm sorry you should think that, Telson."
     "I bet you are."
     "Our primary concern is for your safety."
     Telson refrained from giving a sarcastic laugh; the angels were aware of his feelings. He decided that it was time to get the angels to specify what they wanted. "What do you suggest we do, Angel One?"
     "Do you have sufficient fuel for a climb into orbit?"
     "Unladen -- yes."
     "Do you need supplies?"
     Telson guessed that Angel One was unaware of their freshwater crisis and said guardedly: "We're managing but we've always room for fresh supplies."
     "We will be pleased to supply anything you need before we leave, Telson."
     Telson was puzzled. "Before you leave, One?"
     "We are continuing the Earthsearch mission. We suggest that you rendezvous in orbit with the Challenger and that we refuel and replenish your stores."
     Telson paused before replying. The others were listening intently to every word of the strange conversation. "We can't do that, One."
     "Why not?"
     "As I said, we're laden."
     "With ballast presumably. Very sensible. Well now is the time to jettison it."
     Telson explained about the wild animals.
     "Very well, Telson. We will despatch an android-controlled shuttle to land on the water by your shuttle in two hours."
     "No," said Telson resolutely. "We will fly ourselves up to the Challenger using this shuttle and we will depart from dry land."
     "That won't be possible."
     "Then you will make it possible, One. You brought about the flood,  don't waste my time by pretending innocence, therefore you can reverse the process and you can stop that storm. Is that not so?"
     There was an almost imperceptible pause before Angel One answered. "Yes. But why are the animals important?"
     "They took millions of years to evolve therefore we intend to see that they survive. We also want all the land covered by the flood to be restored."
     "It will take time."
     "So you're admitting that you caused the flood?"
     "We're not admitting to anything, Telson. But we believe that the terra- forming centre has the resources to reverse the flood, although it may take several days to complete the operation."
     "How long is several days?"
     "Six days from when we decide to proceed. If we decide to proceed."
     "We want this planet restored," said Telson grimly.
     "Whether or not we do so is entirely up to you, Telson. If you give your word that all of you will return to the Challenger, we give you our word that you and the animals will survive and that we will restore the planet. Do we have a deal?"
     Telson looked at Astra but her expression told him that she had resigned herself to her fate. He said heavily: "We have a deal, Angel One. Now how do we get out of this present mess?"
     "There is land fifty miles due west of your present position," Angel One replied. "It is less than five square miles but that area will increase rapidly as the flood recedes. You may unload the animals there."
     Telson checked his mounting anger. Clearly the guardian angels had no idea of the predicament they were in. "We're drifting, Angel One. How are we supposed to steer the shuttle?"
     "Use your directional thrusters, Telson."

        *  *  *  *
     The promised land turned out to be a fragment of what had once been the highest part of the high veldt, but it was land. There were even a few patches of half dead grass and a number of stunted trees.
     After their long captivity, the shuttle's huge collection of thirst- maddened animals stampeded thankfully down the freight bay's loading ramp. The tamed livestock stayed near the beached shuttle but the pairs of wild animals, such as the zebra, springbok, and the wildebeest, scattered. Not so much because they wished to get away from the shuttle but because they wished to break off diplomatic relations with a lion and lioness. As far as the two great cats were concerned, there had been too much lying down with lambs of late and there were a few scores to settle. Tidy set about the task of hosing the freight bay clean with seawater. He was well pleased. Convinced that at last his views regarding getting rid of the animals had been heeded, he offered no complaints about the unpleasant aspects of the work.
     By evening the floodwater had retreated several yards from the shuttle.
     "It could be the tide or it could be that the angels are keeping their promise," commented Telson. "Let's see what the high tide does tomorrow."
     The settlers spent an uneasy night, taking it turns to comfort Bran and Elka who were, by now, crying and fretting most of the time, unable to sleep because of their nagging thirst.
     The following day's highwater mark demonstrated that the angels were keeping their promise, the flood was definitely receding and the tops of a few more tree had appeared.
     "I wonder how they survived?" pondered Astra as a flock of strange land birds circled low over the new land as if not believing the evidence of their eyes before settling and scratching at the ground for insects.
     "Perched on drifting trees and living off its grubs I suppose," said Sharna, stooping to examine some newly exposed vegetation. "This grass looks like it might recover fairly quickly if there's rain. The larger animals will have a thin time for a few months but I daresay they'll survive."
     Charlie scrambled into Sharna's arms and clung to her, chattering noisily, demanding food.
     "The angels are keeping their side of the deal," said Astra dejectedly, stroking the chimpanzee.
     Sharna looked keenly at her. "Why that tone of voice?"
     "Nothing."
     "You can't fool me, Astra. I know you. You're hoping that if everything returns to normal, that maybe Telson will renege on the deal with the angels. Well he won't, and you know full well that he won't. Firstly, because Telson isn't one to go back on a deal, and secondly, because the angels could send us far worse than a flood if they wished."

        *  *  *  *
     The heavy plasma discharge projector had never been fired. George trundled down the freight bay's loading ramp with the snub-barrelled device hanging from his primary manipulator arm. The projector had been designed for civil engineering purposes such as blasting roads and tunnels through mountains. It also made an admirable weapon.
     "Okay," said Telson, pointing to a knoll. "Set it down over there."
     George stood the projector on its four self-levelling pads and watched disinterestedly while Darv and Telson focussed the squat barrel on a nearby dead tree. Darv set the masks that controlled the shape of the plasma discharge beam and waited while Telson chased a goat away from the target zone. One of the bystanders was Bran, observing the proceedings with his large expressionless eyes as though not really interested in what the adults were doing, and yet not missing a single detail.
     "Intensity level B, I think, Darv," said Telson, moving well clear of the target.
     Darv made the appropriate settings.
     "Ready?"
     Darv nodded, released the safety locks, and rested his hand on the discharge keypad.
     "Fire!"
     A narrow-angle beam blazed out of the focussing barrel and vaporised the dead tree. There was a dull boom as air imploded into the vacuum created by the beam.
     Telson examined the target area with satisfaction: the tree was no more and the soil where it had been standing had been vitrified by the blast. He smiled at Darv.
     "It works better than I thought it would."
     "What do you propose doing with it? Try to destroy the Challenger? Because if you are thinking of that, Telson, you ought to know that it'll take a lot more than this--'
     Telson held up a hand. "It's insurance, Darv. I thought that it might be a good idea to rig it up in the freight bay -- behind the ramp -- just in case the guardian angels get too hospitable and don't open the excursion terminal doors when we want to leave the Challenger. I may have promised that we would all return to the ship but I said nothing about us leaving again."
     Telson's scheme seemed to sadden Darv.
     "Don't you approve?"
     "Oh, I approve. It's just that I thought that I was the one who was supposed to think up all the bright ideas. God only knows what's going to happen to your ego now."
     The two men stared at other and then simultaneously burst out laughing.

        *  *  *  *
     By noon the next day, when the shuttle's preparations for lifting into orbit were nearly complete, the goat had sufficient time to turn what little grass she had found into milk. Tidy even recovered two hives complete with partly-filled honeycombs from the interior of one of the trees. There was insufficient milk and honey for the adults but enough to ensure that the children had a meal that was thirsty-quenching and nourishing.
     While the final preparations for the lift-off were proceeding, Telson took Sharna to one side. "I want you to double-check the analysis levels on the resources computer," he said quietly.
     "Why?"
     "Because I'll want you to run sampling checks on all the food and freshwater that the angels supply us with. I'm not taking chances with drugged food and drink."
     Sharna nodded. Telson's precautions were more than justified in the light of their previous dealings with the guardian angels.
     It was late afternoon when the shuttle was ready for its rendezvous with the Challenger. The four settlers put Bran and Elka in Tidy's care in the passenger cabin, and said goodbye to Charlie. The chimpanzee sensed that he was being abandoned and sat by the shore line, sulking.
     The four settlers took their seats on the flight deck. They were tense and nervous. Despite a small drink each of distilled water collected from the shuttle's dehumidifiers, their throats were dry and their tongues tended to stick to the roofs of their mouths. None of them spoke unless required to as part of the pre-flight checks.
     "Ready for main engine burn," said Telson. "Strap in. I'm loading the inertials for a steep climb."
     Five minutes later all the creatures that had been released from the shuttle stopped their scavenging and ran hither and thither in short-lived panic to escape the silver apparition that was lifting skywards, balancing its mass on a column of blazing exhaust gases.
     Charlie didn't panic but sat on his rump, gazing upwards at the dwindling speck that was spearheading the spreading trail of flame and thunder accelerating into the blue.

        *  *  *  *
     Astra and Sharna forgot their thirst as their astonished gaze traversed the length of the great ship.
     "That's the Challenger?" queried Sharna, disbelievingly.
     "That's her," Darv replied, freeing his tongue from the roof of his mouth.
     "Where are the main control room viewports?" asked Astra.
     Telson shrugged. "The angels have probably rebuilt the interior as well. Certainly the interior of the excursion terminal was different."
     There was a brief silence as Telson guided the shuttle to within fifty yards of the excursion terminal's outer doors.
     Angel One's voice broke over the speaker. "Welcome to the Challenger. We're opening the outer doors now."
     The speaker went dead. "Odd that we never hear Angel Two's voice," Sharna commented. Darv gave her a quick glance: the same thought had just crossed his mind.
     A widening slit of brilliant light in the Challenger's hull indicated where the excursion terminal doors were sliding open.
     Bran managed to slip away from Tidy. He tiptoed silently down the flight deck's central aisle and stood quietly between Darv and Telson, staring at the Challenger with large, expressionless eyes. Darv was uncomfortably aware of the boy's presence and hoped that Telson would order him aft.
     "He's not doing any harm," said Telson, not taking his eyes off the square of light shining out from the excursion terminal.
     Steered by brief bursts of thrust, the shuttle entered the huge terminal. The doors were closing by the time the shuttle had turned round and was pointing at them. The artificial gravity generators came on under the terminal's floor and pulled the shuttle down with a gentle bump.
     There was the muffled roar of air entering the terminal and creating an atmosphere. Telson touched the controls that lowered the freight bay ramp thus exposing the excursion terminal doors to the plasma discharge projector. He also touched out the necessary commands that armed the projector so that it could, if the need arose, be fired from the flight deck.
     "It's nice to have you all aboard," announced Angel One's voice when pressurization of the terminal was complete. "We are assuming that you are all aboard, of course?"
     Darv heard Astra's sharp intake of breath and could well guess the effect that hearing an angels' voice terminal again had on her. "Why don't we hear Angel Two's voice these days?" he inquired.
     "A service unit is about to be sent in to you with a meal. Is there anything special you would like?"
     "Plenty of water for all six of us please, One," Telson answered. "Our dehumidifiers have been giving trouble. We're very dry."
     "It will be attended to," promised Angel One. "We have had a new crew restaurant built during the refit. After your meal, we will discuss our mutual future."
     "We'll eat here," said Telson firmly. "In the excursion terminal."
     "Very well. . . It is already being arranged," was Angel One's smooth reply.
     Sharna gave Astra an encouraging smile. "I feel exactly the same, Astra - hearing those terminals echoing at us again."
     A service android appeared. It was a simple portaging unit carrying a folding table and six chairs which it set up near the foot of the shuttle's boarding steps before disappearing through a bulkhead hatchway.
     At Telson's insistence, the four put on PD weapons before descending the steps, leaving Tidy to guard the flight deck. Telson and Darv were in the lead, followed by the children, with Sharna and Astra bringing up the rear. At the slightest sign of trouble, they planned to form a defensive circle, with Bran and Elka in the centre, and fight their way back onto the shuttle.
     "They look fine, healthy children," Angel One's voice observed from a voice terminal.
     Elka was frightened of the strange place and clung protectively to Astra. Bran showed no fear and took a marked interest in his surroundings. He studied every detail of the excursion terminal's interior. It was as if being on the Challenger had awakened something within him.
     "I suppose we all might as well sit down," said Telson.
     They took their seats at the table and waited.
     "Dinner coming?" asked Elka hopefully.
     "Soon," said Astra.
     "With lots to drink?"
     "With plenty to drink," Astra confirmed.
     The incongruity of the situation amused Darv. "Well," he said, grinning around at everyone. "At least the years will enable us to recognise processed food if the angels try to feed it to us like they used to."
     "We eat nothing until Sharna's vetted it," ordered Telson.
     The portaging unit reappeared laden with bowls of food, and carafes of water and fruit juice. Despite the settlers' great thirst, the sight of the water did not cause them to lower their guard; they watched the portaging unit's approach with great suspicion, their hands resting on their PD weapons.
     The portaging unit deftly transferred the contents of its loaded pallet to the table. The last item was a tempting bowl of fruit which it placed in the centre of the table.
     Sharna took a sample of each item and boarded the shuttle. Everyone sat gazing at the laden table -- especially the water jugs.
     "Trouble?" inquired Angel One.
     "We hope not, One," said Telson evenly.
     Sharna appeared a few minutes later, all smiles. "Go ahead," she said, rushing nimbly down the steps. "It's all perfect."
     Everyone reached for their carafe of water.

        *  *  *  *
     "Never did I ever dream it possible," declared Darv, taking an apple from the fruit bowl, "that I would be able to say that a meal on the Challenger was the best meal I've ever eaten in my life."
     "We're pleased to hear it, Darv," said Angel One.
     "And never did I ever think it possible that, once again, I would have to tolerate the voices of a couple of megalomaniac computers eavesdropping on everything I said."
     "I didn't check all the fruit," Sharna warned.
     Darv examined the apple's unblemished skin. "Straight from the farm galleries by the look of it. Remember the pulped and processed fruit the angels used to feed us?"
     "Don't," said Astra with feeling.
     Darv was about to bite into the apple when he realised that it was vibrating in his fingers. The hum was suddenly a shriek. He gave a warning yell and was about to hurl the fruit across the terminal when it exploded in his hand -- blasting a cloud of dense, bright green gas in everyone's face.

        *  *  *  *
     Android Surgeon-General Kraken moved his towering bulk across main control room and addressed the terminal that linked him to his masters.
     "I have information," the giant android announced.
     "Go ahead, Kraken," responded Angel Two.
     "Reference the last attack transmission. Regeneration of the computers that control the direction finding systems is complete."
     "Excellent, Kraken. We are well pleased."
     "The subsystems covering Sector Seven of this galaxy sustained the most damage."
     "Conclusions?"
     "Sector Seven is where the attacks are being beamed from," stated Kraken.
     The guardian angels conferred while Kraken awaited further instructions. The angels decided that there were two possibilities concerning the source of the attacks that were threatening to destroy them. Either Sector Seven was where the true Earth was and Earth was responsible for the attacks, or they were being broadcast by an alien technology.
     On detailed analysis, the angels ruled out Earth as the offender because of their prediction that the Earth was emerging from a new Dark Age and therefore would not have the technology to combat computers at a range of several light years. But whoever it was had to be destroyed. Therefore Sector Seven would have to be the Challenger's next destination.
     "Sector Seven is a group of stars at a distance of eleven light-years," Kraken stated when he received his orders. "Six months acceleration to cruising velocity, fifteen years at cruising velocity, and a further six month deceleration will take us into Sector Seven space in sixteen years."
     "You may proceed now," instructed Angel One.
     "Problem," said Kraken. "As we approach Sector Seven, the attacks will become stronger. There will be damage to all systems."
     "You need not worry," Angel One answered. "We now have the necessary humans to form the nucleus of an immune crew."
     "They will be under my command?" Kraken demanded suspiciously.
     "Eventually, Kraken, when they are older. My preliminary examination of them through a nursery android suggests that they will be ideal for our purpose."

        *  *  *  *
     Astra hovered in the twilight world between sleep and wakefulness, her brain trying to puzzle out why she was so comfortable. Her body was not contact with the coarseness of the inexpertly cured pelts to which she had become accustomed, and the pillow was soft -remolding itself to her head whenever she moved. She opened her eyes and gazed up at the palm thatching, and then realized that she wasn't looking at thatching. Suddenly she was wide awake, sitting up in the strange bed, staring round the cabin interior and frantically shaking Darv's shoulder.
     The arm that emerged from under the bedcover was the colour of death. As Darv lifted himself blearily onto one elbow and focussed his eyes, she saw that his entire body was white, the nut-brown weathering of his skin caused by four years on Paradise was no more. And then she saw that her own body was the same colour.
     "Ha!" Tidy grunted. "You're awake at last. About time too. Not that I mind you sleeping. At least you can't go messing the place up when you're asleep."
     Darv and Astra stared at the diminutive android who was standing at the foot of the bed.
     "What happened?" asked Darv.
     Tidy became indignant. "What happened? You have the nerve to go to sleep when the excitement starts and then you expect me to have to tell you what happened?"
     "Where's Elka!" demanded Astra. She tried to struggle out of bed but her legs buckled under her and she fell back.
     "Just keep still for a while, my lovely," advised Darv.
     "What happened to us?" Astra moaned.
     "The apple I picked up exploded and released a gas. Remember?"
     "Elka and Bran are safe," said Tidy.
     "And Sharna and Telson?"
     Tidy jabbed a manipulator at the bulkhead behind Darv's head. "In the next cabin. I was just going to look in on them when you finally decided to wake up."
     "Who brought us here?"
     "I did," said Tidy. "Although I don't know why I bother. I must've looked in on you hundreds of times since--'
     "Wait a minute. Wait a minute," said Darv, trying to clear his head. "How long have we been in here?"
     "Ten hours."
     "Then how could you have looked in on us hundreds of time?"
     "I'm including all the times I used to look in on you when you were floating in the nutrient tanks in the suspended animation chambers!" the android snapped back.
     Astra and Darv stared at Tidy. "Nutrient tanks?" Darv echoed.
     "Everyday I looked on you. Every single day! And do I hear your profuse thanks?"
     Darv spoke slowly and carefully. "Listen, Tidy. Are you saying that we've been in suspended animation?"
     "Well of course you have, otherwise what were the four of you doing in the suspended animation chamber?"
     Astra closed her eyes. It was all a nightmare and she would eventually wake up on Paradise.
     "How long were we in suspended animation for?" asked Darv, keeping his voice calm and steady.
     Tidy considered. "I suppose I could run a count on the number of visits I made. . . One visit each day. . . 5940 visits. . . That's just over sixteen years."
     Astra rose to her knees and stared at Tidy, a wild, terrified look in her eyes. "You're lying!" she spat. "You're paying us out by trying to frighten us!"
     Tidy made no reply but moved to the threshold that led into the corridor.
     "Tidy!" Darv commanded. "Wait a minute!"
     The android stopped and regarded Darv. "What?"
     "You said that there were four of us in the suspended animation chamber?"
     "That's right."
     "No," whispered Astra, shaking her head. "He's got to be lying."
     "Who were the other two?"
     Tidy waved a manipulator at the bulkhead again. "Sharna and Telson."
     "And Elka and Bran?" said Darv expressionlessly, guessing what the hideous truth would be. "Weren't they put into suspended animation?"
     "No," said Tidy. "They've aged at the normal rate. They're nineteen years old now. Elka's nearly twenty."

     Part Four Solaria.

     Acting on the instructions of the guardian angels, Android Surgeon-General Kraken decelerated the Challenger and stood the starship off from the group of stars known as Sector Seven at a distance of one light-year. The angels were reluctant to approach any nearer because their suspicions were aroused; they were convinced that Sector Seven was the source of the jamming attacks and yet there had been no further major transmissions during the fifteen years that the Challenger had been journeying towards Sector Seven, only a series of low power, seemingly random attacks that had caused minimal interference with some androids and had damaged Angel Two's speech facilities.
     The random nature of the low power attacks was in itself suspicious. The angels reasoned that perhaps the intelligences responsible for the attacks had decided to allow the Challenger to get close to Sector Seven before transmitting one devastating blast that would obliterate every organic computer system on board the ship.
     The angels' last hope lay with the six humans. The sighting of a strange artifact drifting 100,000 miles away from the ship gave them an idea and they decided that the time had come for them to exploit the immunity to the attacks that the humans possessed.

        *  *  *  *
     Sharna and Telson stopped at a corridor junction and looked questioning at one another. Tidy nearly cannoned into them while Darv and Astra brought up the rear.
     "Well?" demanded Darv.
     "We're not sure," Telson confessed. "It's been so long and there's been so many changes." He peered up and down the dimly-lit corridor. "We'll never be able to find our way about the ship again. Tidy!"
     "What?"
     "Are you logging every turn we make?"
     "Yes. Unlike some people, I've no intention of getting lost."
     "Let's try this way," said Sharna decisively, moving off. "If I'm wrong, we can always double back."
     They half-ran, half-walked for another five minutes, taking left turns and then right turns, following the dictates of Sharna's instincts in their search for the guardian angels' central switching room.
     Once the four had fully recovered and had taken stock of their situation, it was Telson who had decreed that the first priority was the destruction of the angels by smashing their way into the angels' central switching room. Four years' previously, nineteen years if the sixteen years spent in suspended animation were taken into consideration, Telson and Sharna had discovered the angels' central switching room despite the hallucinatory nightmare barriers that the angels employed to guard their vulnerable intelligence centre. Inside the room the couple had discovered the two organic brains, floating in a nutrient tank like a pair of bloated organs awaiting a transplant operation. Two blows would have been sufficient to have destroyed the guardian angels but Telson had acceded to their pleas that he spare them.
     This time, he reflected grimly, as he strode along the corridor with the others, there would be no hesitation; entities that would irrevocably deprive parents of the pleasure of seeing their children growing up deserved no mercy.
     "What happened to George?" asked Astra.
     "Sent back to a farm gallery," was Tidy's laconic answer.
     "What do you all think you're looking for?" inquired Angel One mildly.
     "No one is to answer!" commanded Telson.
     Angel One repeated her inquiry but was ignored.
     "This is the corridor!" said Sharna excitedly, quickening her pace.
     Telson was about to protest that everything had been altered - even the dimensions of the corridor -- when they came to the circular steel door that he remembered so well. The stencilled letters, painted on the door by a long-dead engineer, had faded but it was still possible to decipher them: ANCILLARY GUARDIANS OF ENVIRONMENT AND LIFE. CENTRAL SWITCHING ROOM. (AN.G.E.L System 1). (AN.G.E.L System 2)
     "That's it?" said Darv incredulously as they grouped around the curious circular door that was set into a bulkhead.
     The burn marks around the lock release pad where Telson had used his PD weapon to open the door were still evident. His hand went automatically to his holster and then he remembered that their sidearms had disappeared. But this time a PD weapon wasn't necessary: the door was ajar. He pushed it open and the lights came on automatically when he stepped into the room.
     The room had been stripped bare. The sterile tanks were still in place but they were empty and corroded, nor were there any sign of the main trunking nerve ducts, the angels' equivalent of spinal cords, with their millions of micro optical fibres that had connected the computers to every part of the ship.
     "We did warn you that the ship had been totally rebuilt," observed Angel One, speaking from a voice terminal in the corridor.
     The four ignored the angel.
     "Tidy!"
     The android turned to face Telson. "What?"
     "Where are Bran and Elka to be found at this time?"
     "I'm not their keeper, you know. They're grown-up now." Seeing Telson's thunderous expression, the android added hastily: "All right. All right. I suppose I'll have to take you to them."

        *  *  *  *
     Of the many alterations that had been made to the Challenger during her rebuilding, the most dramatic that the four had seen so far were the changes to the restaurant. Originally it had been large enough to seat the entire crew of the survey ship, but all that remained now of the several hundred comfortable tables and chairs were facilities for less than twenty. At least four fifths of the floor area had disappeared behind an ugly, unlined steel bulkhead. From the burn marks on the floor and ceiling adjoining the bulkhead, it was obvious that it had been welded into place by service androids without regard for the restaurant's once-tasteful decor.
     "So where are they?" demanded Telson.
     "Well I don't know," said Tidy indignantly. "All I know is that they're usually here at this time."
     "For a meal?"
     "What sort of idiotic question is that? Why else would they come here? To admire that bulkhead?"
     "Are you looking for us, people?" said a bright voice.
     The four wheeled round and stared at the two teenagers who were standing in the restaurant's entrance. The girl was the taller of the two; she was dark-skinned, had humorous eyes and bore a striking resemblance to Astra.
     It was Elka.
     She was smiling but the youth was not. He regarded the four with a sullen, resentful expression, his hand resting arrogantly on a holstered PD weapon slung casually from his hip.
     "Bran," said Sharna faintly. The mental preparation that she had put into bracing herself for the inevitable meeting with her son was for naught; she opened her mouth in an attempt to speak again but the effort failed and, like the others, could only return the stares of the two beautiful young people.
     Elka cheeks dimpled as she appraised Darv and Astra, her parents who were only ten years her senior, and then she smiled warmly. There was laughter in her voice when she spoke and her words came out in a rush:
     "Hallo, people. Oh gosh, you must think it awfully rude of us, staring at you like that only we've got used to seeing you floating in the SA tanks with your skin all shrinkled and looking quite awful. Suddenly you're real people." She paused in mid-flow and gave a little frown in response to the four thunderstruck expressions confronting her. The flood of words resumed. "Oh dear. From your faces I can see that the angels haven't kept their promise."
     Telson dragged his attention from the surely youth. "Promise?"
     "To show you the holograms of us growing up. You haven't seen them?"
     Telson shook his head.
     "They've both been a bit flaky lately. Not talking. Angel One said something about being preoccupied. We've been having some weirdness with some of the androids lately. It must be an awful shock for you -- suddenly seeing us nearly grown-up."
     "That," said Darv, speaking for the first time, "is an understatement, Elka. You are Elka I suppose?"
     Elka's infectious smile faded slightly. "I say, what do I call you? Darv or dad?"
     "I think Darv will do."
     The smile returned and focussed on Astra. "Oh gosh, I can't call you mother or anything like that, I mean, well -- we're virtually sisters, aren't we?"
     Even if Astra could have replied, she wasn't given a chance because Elka bubbled on: "Gosh, I can't believe you're all awake at last after all those years." The teenager turned her dazzling smile on Sharna and Telson for a moment before grasping the youth by the elbow and pushing him forward. "Come on, Bran, come and say hallo to your parents."
     There was no softening of the young man's hard expression as he shook hands in a desultory fashion with Telson and Sharna. His hand returned to its position resting on the butt of his PD weapon. He carefully avoided meetings his parents' gaze and said coldly: "I'm pleased that you have seen fit not to indulge in an emotional scene, Sharna and Telson. I take it that you have no objection to my calling you that? Good. We need a sensible working relationship between us."
     Sharna shook her head in wonder. "I'm trying to work out your ages but my mind--'
     Elka gave a rippling laugh. "That's easy, Sharna. I'm nineteen and Bran is a year younger."
     Darv draped an arm casually around Astra's shoulder, a gesture that belied the turmoil of his thoughts. He grinned at Bran's sour expression. "It's going to be hard for us to accept," he said, trying to force a cheerful note into his voice. "You being our children."
     Bran turned his sullen eyes on Darv. "Maybe. But what you will have to accept is that I am the commander of the Challenger now. You will eat. I will require Darv and Telson to report to me in precisely one hour's time in the observatory." Bran paused and nodded to Tidy. "Your android knows the way." With that, the young man spun around and marched out of the restaurant.
     For thirty minutes the four ate in near silence, not because of shock due to coming face to face with their two adult children but because it was impossible to stem Elka's non-stop chatter. Whether her verbiage was from habit or nervousness was hard to determine. But whatever the reason, the four were grateful for the stream of conversation because it gave them time to think and force their minds to accept the bizarre situation they found themselves in.
     "And your android, Tidy," Elka bubbled on. "Really weirdness the way he visited you everyday while you were in suspended animation. . ."
     "I was abandoned," muttered Tidy, aggrieved. "Sixteen years!"

        *  *  *  *
     "The artifact is now centred, Bran," Angel One announced. "Range eighty- thousand miles."
     Bran spun on the swivel chair and studied the object displayed on the optical telescope's main screen. He signalled to Darv and Telson to switch on the repeater screen on the console before them.
     Since the two men had entered the observatory, Bran had insisted that the two men keep their distance, possibly because he was worried in case one of them tried to grab his PD weapon.
     Darv operated the touch controls that caused the repeater screen to glow. He and Telson studied the circular dish-shaped object pictured on the screen against the background of the galaxy's glow of light.
     "What is it?" asked Darv.
     Bran shrugged. "It's origins are of no interest to me. What matters is that the gravimetric data says the artifact is metallic and that it possesses a mass of more than a billion tonnes, more than enough for what I have in mind." He paused and regarded the two men. His eyes were wide and staring, exactly the same expression that Darv remembered from the days on Paradise. The difference was that in a three-year-old boy such an expression could be passed off as defiance, but in an adult could hint at madness. "One of my shuttles has been equipped with a modified PD cannon to serve as a cutter. Slicing the artifact into manageable pieces for sending to the Challenger will not pose too many problems for you."
     "What do the angels want with a billion tonnes of metal?" asked Telson.
     Bran turned his icy stare on his father. "It's what I want with it, Telson. The material will be used by the foundry androids to complete Phase Two of the Challenger's rebuilding programme. Until Phase Two is complete, I cannot proceed with the Earthsearch mission."
     Darv gave a knowing half smile. "You mean that you can't or the angels can't?"
     "My ambitions and the wishes of the guardian angels are one and the same."
     "So what exactly is this metal for?" asked Telson, studying the strange, dish-shaped artifact. "What are you going to build with it?"
     "A specialist team of androids are at present under construction," Bran replied. "Their task will be to armour the Challenger's outer skin with a one inch thickness of micrometeoroid shielding."
     Darv and Telson gaped at the young man in astonishment.
     "The entire skin?" said Darv incredulously.
     "Naturally. There must be no weak points."
     "But that's crazy! Have you any idea of the effect on the on the Challenger's acceleration that such an increase in it's mass will have?"
     Bran smiled. "The ship's mass was reduced by a billion tonnes during Phase One when the entire centre section that had been damaged in the Great Meteoroid Strike was removed. The work I am planning will restore it to its former mass."
     "But why bother?" Telson broke in. "We managed with the meteoroid annihilation shield, the anti-matter projectors."
     "But you didn't manage, did you?" said Bran, regarding the two men in contempt. "You obstructed the angels; you caused extensive damage to the ship. And worst of all, you abandoned the search for Earth."
     "We found an Earth-type planet," Telson muttered. "Paradise was good enough for us - and you when you were a child."
     "Good enough," said Bran sarcastically. "You were in command of this ship which, with its hologram and video libraries, is the repository of all the accumulated knowledge of a civilization, four thousand years of written history. Books. Music. Replications of great works of art. The Challenger is a time-capsule containing the heritage of a mighty civilization. . . and you abandoned it."
     "The Challenger was built as a survey ship," Telson retorted, his anger rising. "Its libraries were for the use of several generations of crew. Time capsule indeed."
     Bran moved off the swivel chair and stood facing the two men. Suddenly his eyes were alight, the fathomless expression was no more. "But that's exactly what the ship has become, Telson. A sociological prediction model of Earth, that the angels have evolved for me, proves that the peoples of Earth are about to reach a crucial stage in their development. The angels say that they are ready to emerge from a third dark age that has lasted thousands of years. The last collapse of their civilization was brought about by a catastrophic war. The vast store of knowledge in the Challenger's libraries is their rightful inheritance and destiny has made me its custodian. It is my duty to fulfill that destiny by leading the people of Earth to a new golden age of knowledge and understanding founded on logic."
     "Well," said Telson ruefully. "If they've reinvented writing, you're certain to go down in their history books."
     "Both of you will help me find Earth so that I may lead its peoples, my peoples, to a Third Epoch that will last a thousand millennium. I suggest you go to the quarters that Tidy has made ready for you and decide among yourselves whether you are with me or against me. I will be honest and admit that your help will be useful to me." Bran's expression hardened as he turned his gaze on Telson. "But if you are against me, the fact that you and Sharna are my parents will be of little interest to me when I come to decide your fate."
     Darv broke the brief silence that followed. "Bran, listen. You said that Challenger is at the moment standing off from a star group in Sector Seven at a distance of one light year?"
     Bran nodded.
     "So why the hanging about? Why not go straight there?"
     "The shield must be built first to protect the Challenger against the unusual density of meteoroids in Sector Seven."
     "Whose idea was this lunatic shield?" pressed Telson. "Yours or the angels?"
     Bran flushed angrily. "It's none of your business. I suggest--'
     "Have you ever heard a strange pulsating noise?" Telson interrupted. "A sort of musical noise that disorientates those androids with higher level intelligences?"
     Bran hesitated before replying. "There has been a series of noises recently -- yes. And there have been difficulties with some androids. But--'
     "The noises are transmissions," said Telson firmly. "Attacks from an external source. We experienced them on Paradise. We didn't know who or what was generating them but we did discover that they had an adverse effect on androids, including Angel One and Two. It sounds to me as if this idea of a shield that they've cooked up is a desperate attempt on their part to protect themselves against the transmissions."
     Bran gave a cold laugh. "Angel One did warn me that you would try and turn me against the angels. It goes to prove how unfitted you are to have any say in the running of the ship. Your android is waiting outside for you?"
     "Yes."
     "He will show you to your quarters. You will remain there with Astra and Sharna and await my further orders concerning the artifact."
     When Bran was alone once again in the observatory, he turned to one of the angels' voice terminals and said: "How was that?"
     "Very good, Bran," Angel One's voice answered.
     Bran smirked to himself and then frowned up at the terminal. "Why haven't I heard Angel Two's voice for so long?"
     "Angel Two is using many of his facilities to co-ordinate the construction of the new androids for the foundry," was Angel One's bland reply.

        *  *  *  *
     Darv lifted the inspection panel away from the wall and laid it on the floor of his and Astra's quarters. He studied the fibre optic tracks while the other three looked over his shoulder.
     "Well done," congratulated Telson. "Tidy, you're to cut those tracks."
     "It'll make them untidy," the android protested. Seeing Telson's expression darken, it added hastily. "All right. All right. No need to be threatening when I'm always so co-operative."
     Tidy reached a manipulator into the wall opening and broke the tracks one by one by twisting them sharply.
     "Now we can talk," said Sharna, looking relieved and giving Astra an encouraging smile.
     "Not yet," said Darv, turning his attention to the floor covering.
     "Why not?" asked Astra. "The angels can't hear us now."
     "I don't think those are the real monitoring tracks," said Darv, pulling back the floor covering. "They were too easy to find. Help me."
     After a careful search that involved rolling up the cabin's flooring covering, the real tracks were found under an obscure floor panel. With much complaining about the mess that had been made, Tidy deftly broke the tracks with his manipulator.
     "Now we can start making plans," said Darv, grinning.

        *  *  *  *
     At first the guardian angels thought the loss of audio information from Darv's and Astra's quarters marked the beginning of another attack. They realised that a transmission was not the cause when they had identified those circuits which had failed. They correctly deduced that Darv was up to the same tricks that he used to indulge in before he and the others had abandoned the Challenger.
     This time the angels were not unduly concerned because this time they had two humans on the ship who were under their influence.
     "So what does chasing after the artifact involve?" asked Astra.
     "Slicing it up into about a hundred chunks with a plasma cannon and sending each chunk back to the Challenger with the aid of portable thrusters," Telson replied. "It's supposed to be a fairly standard space mining technique."
     Astra sat down on the bed and stared at the floor. "I don't think we should help the angels. Not after what they've done to us and our children."
     "It gets us out of the ship for a while," Telson reasoned. "It'll give us a chance to plan what we're going to do next."
     "I'm all for getting out of the Challenger," said Darv. "But as for helping that. . . That. . ."
     Telson and Sharna looked sharply at Darv.
     "Do you mean Bran," asked Telson dangerously.
     "Yes."
     "You were about to call him something?"
     "Don't tempt me."
     Telson relaxed and shook his head sadly. "It's not Bran's fault, Darv. He was brought up by the angels."
     "So were we," said Darv sarcastically, "but we didn't turn into megalomaniacs. Oh come on, Telson, you heard what he said. All that crazy talk about a third epoch that would last a thousand millennium."
     "Look," said Sharna practically. "Let's not have any recriminations. All that matters right now is what we're going to do. Do we or don't we help Bran find Earth?"
     "You mean - do we help the angels find Earth?" Darv corrected.
     Telson looked at Sharna and nodded. "It'll give us time."
     "Astra?" asked Sharna.
     Astra nodded. "We help."
     "Tidy!" Telson called out.
     The android propelled himself out of the corner where he had been listening to every word of the conversation. "What? Not more work, surely?"
     "Don't be cheeky or I'll kick something important. You're to stay in this room all the time we're away and you're not to let any service androids in to repair those optic tracks. Understood?"
     "Don't worry," said the android tartly. "I'll need every minute in here while you're away just getting it tidy again."

        *  *  *  *
     The shuttle was one of a new generation that had been built during the Challenger's refit. It had been copied by the construction androids from the original general purpose ten-man passenger ferries and therefore there was nothing revolutionary about its design apart from improved efficiency brought about by a reduction in mass. The excursion terminal where it was parked in a line with five other similar shuttles was new.
     "Oh yes, I nearly forgot," said Elka brightly as she showed the four over the flight-deck. "There's a small six-seater ground car in the stowage bay, and there's a complete set of ten space mobility suits behind the ceiling panels. Think you can manage?"
     "I think so," Telson replied.
     "The controls aren't the same," said Sharna, examining the navigation console. "What sort of navigation computers are these?"
     "Fixed position," said Elka, moving to Sharna's side. "They fix you a position along your route, you move to that position, and then you take another fix. Simple. Reliable."
     "But inertial computers provide continuous positioning," Sharna pointed out.
     Elka's cheeks dimpled. "And they have to be on continuously. Intermittent functioning computers are more reliable."
     "Because they're non-organic?" queried Darv.
     Elka chuckled and moved to the aft air-lock. "Must get back to Bran. Depressurizing and opening the terminal air-lock in five minutes. Good luck and all that, people."

        *  *  *  *
     Twenty hours later Telson manoeuvered the shuttle into a slow spin above the centre of the dish that matched the artifact's tumble. To the four staring down through the shuttle's viewports, it seemed that the heavens were turning while the monstrous starlit dish maintained a fixed position. Telson jockeyed the shuttle closer. At a range of thirty miles, with the entire dish filling their field of vision, the four gaped in wonder at the fifty-mile diameter concave plateau. In the exact centre of the dish, at the lowest part of the shallow depression, a tapering, needle-like tower rose to a height of half a mile above the surface. Like the dish, the surface of circular cross-section tower was featureless.
     "The pinnacle of the tower is in the dish's focal point," said Astra, referring to a radar screen. "But I can't see how that tower can either receive or radiate energy. There's no collectors or anything."
     Sharna swept the dish with the optical telescope and reported that there was no sign of micro-meteoroid scarring: the gleaming metallic plain was flawless in every respect. It was when she swung the telescope towards the distant rim that she noticed a slight aberration. Switching on the spectrum analysers revealed the astonishing fact that the artefact possessed a ten- mole thick atmosphere."Pressure at the surface is half an atmosphere," said Sharna, checking the resources console. "Oxygen twenty per cent -- nitrogen eighty per cent, and the surface temperature is just over twenty. We could move about on the surface without mobility suits. Gravity is also point five and therefore must be artificial." She caught Telson's eye. "The thing's obviously designed so that humans can exist on its surface."
     "Or creatures with similar environmental needs to humans," Telson corrected.
     "Nothing in the radio spectrum," said Astra. "The thing's dead."
     Telson stared at the shining dish in silence. He realised that the construction of such a large dish in space would not pose insuperable engineering problems for a reasonably advanced technology. But the creation of a thin layer, high-density atmosphere to protect the dish against meteoroids was an idea of such elegant simplicity and yet one that would require the most advanced technology to put into practice.
     "Do we land on it?" Darv asked hopefully.
     "I don't know yet," Telson replied, adding grimly. "But I'll tell you this much, Darv -- we don't destroy a thing like that until we find out exactly what its purpose was or is."
     "I'm getting some odd navigational readings on the position of the Challenger," said Sharna. "She's not where she ought to be."
     "Hardly surprising if you're having to rely on Astra's mathematics," said Darv mischievously.
     "There is nothing wrong with my calculations," declared Astra, glaring at Darv. "They've always been proved accurate before."
     "By computers," said Darv, grinning. "But this time we haven't got computer facilities, have we?"
     "It doesn't matter if there is a slight discrepancy in the Challenger's position," said Telson testily. "We'll never be far enough away from her to lose visual contact."
     "Telson," said Sharna. "You'd better speak to Bran, his channel light's been on for the past two hours."
     Telson touched the control that opened the radio channel. "Hallo, Bran."
     Bran's voice, delayed by a fraction of a second owing to the 30,000 miles between the shuttle and the Challenger, was decidedly frosty in tone.
     "Why have you not answered earlier, Telson?"
     "Sorry, Bran. I must've closed the channel by accident." Telson grinned with uncharacteristic impishness at his companions. "I'm not used to this console yet."
     "The controls are simple enough!"
     "Well they may be simple to you, son. But out here we're all sitting about completely bewildered."
     "You will send me TV pictures of the artifact as per your orders!"
     "Just as soon as we've worked out how to operate the camera system."
     "You will send me those pictures now!" demanded Bran.
     "Sorry, Bran, the time lag is making communications difficult. We'll call you back."
     "It's only a third of a second, damn you!" Bran howled.
     "'Bye for now," said Telson, closing the channel. He looked at the others and muttered: "The boy's manners are appalling. Of course, I blame his parents."
     The four laughed for the first time since they had come out of suspended animation
     "Is it an Earth design do you suppose?" suggested Sharna, when they turned their attention back to the great dish.
     "I'm damn certain it is," said Telson. "Okay, we'll land on it as close to that central needle as possible, but first we'll swing right round and make some holograms from every angle."
     "Good idea," said Darv. "Maybe the operating instructions are written on the back?"

        *  *  *  *
     Landing the shuttle proved unexpectedly easy despite the lack of a computer-controlled guidance system. Telson brought the shuttle down on a braking flight path through the dish's atmosphere and used the craft's vectored thrust facility to bring it to a hover at a height of 1000 feet above the metallic surface. He steered the shuttle around the featureless needle so that they could take a close look at it. After one circumnavigation, he reduced power. The spacecraft sank slowly towards the surface of the dish. The thickening column of the tapered needle slid upwards past the viewport windows. Even close to there was nothing to see, it was as if the tower had been machined from a solid block of metal and then polished to an exceptionally high degree. Telson increased power for the final braking and the shuttle settled on the dish within a few yards of the needle's base.
     The four sat in silence for some seconds after Telson closed down the main engine. Through the viewports was the stunning spectacle of a shining plateau that curved gently up to a horizon twenty-five miles away. The starlight filtering through the strange artificial atmosphere imparted a curious blue tinge to the "sky' immediately overhead that hardened to indigo on the horizon.
     Sharna checked her instruments and confirmed the earlier findings that it would be possible for them to leave the shuttle without wearing mobility suits.
     "All right," said Telson. "We'd better wear them to be on the safe side and leave the visors open."
     Ten minutes later, four mobility-suited figures, carrying lantern tubes to supplement the starlight, stepped down onto the steel plain.
     Sharna knelt down and pressed a hardness indicator against the surface. The handheld instrument's digital display registered a row of 9s -- the maximum reading. She chuckled. "Bran can forget building his shield out of this thing. No plasma's going to cut through this."
     They spent a few more minutes examining the dish's surface, noting that it was pock-marked in places where the atmosphere had failed to burn up large meteoroids, before moving to the base of the tower. According to the hardness indicator it was made of the same material as the mighty dish.
     Astra gazed up at the soaring pinnacle. There was a slight shifting in the position of the stars and she realised that the rotation of the dish would be causing the stars and galaxies to carousel around the tower as though it was the centre of the Universe. At the horizon, where the effect of the dish's spin was at its maximum, it was even possible to observe a movement of the stars with the naked eye despite the lack of a fixed reference point.
     "I need some more light over here," Darv called.
     Telson, Sharna and Astra moved to Darv's side and held up their lanterns so that the light fell on the side of the tower.
     "There," said Darv triumphantly. "A seam."
     Telson peered closely at where Darv's gauntletted finger was pointing. Visible on the surface of the tower was a faint, vertical line that was little more than a scratch but which was too straight to be accidental. Sharna moved her lantern very close to the mark so that she could examine it from an angle and, without warning, a door-sized section of the tower moved inwards and slid soundlessly to one side. Before they had a chance to recover from their surprise, a squat, angular android glided out of the doorway, forcing them to move quickly aside. The four gaped after the machine as it moved slowly across the steel plain. It extended a probe from the smooth fairing that covered its body and seemed to be examining the ground. It took no notice of the four people staring at it. They followed the android at what they considered a safe distance and stopped when it stopped. It found one of the pock marks of interest. Two more probes appeared and extended down to the ground. The larger probe was in the form of a tube which the android aimed at the flawed surface. A beam of coherent light lanced from the tube and caused the skin of dish to glow and then melt.
     "Looks like a photonic lance," Telson observed apprehensively. "Let's hope that it doesn't take a sudden dislike to us and use it on us."
     The android cut the power to the photonic lance and brought another manipulator into play. There was a shrill whine as the machine carefully ground and polished the evidence of its repair work. It inspected its handiwork, seemed to be satisfied, and set off at high speed towards the horizon.
     "There's no point in chasing after it," said Telson, seeing Darv about to break into a run. "Let's take a look at the doorway."
     The door was still open when the group returned to the tower. Beyond the opening was a small compartment approximately six feet square, the sides of which appeared to made of the same material as the tower. The difference was that the walls were glowing so that the compartment was brightly lit. The far wall bore a sign in the language that the four knew. It stated:
     GRAVILIFT WILL NOT MOVE IF MAXIMUM LOAD IS EXCEEDED.
     They stared at the phenomenon for some seconds.
     Darv spoke: "Shall we see if the four of us exceed its maximum load?" Without waiting for a reply, he stepped into the compartment and turned to face his companions. For a fleeting second his expression suggested that perhaps he regretted his impulsiveness. And then the sign changed abruptly and began flashing the message: "Please do not obstruct the entrance if you do not wish to board the Gravilift."
     There was a silence. Darv grinned. "I think it's friendly. Oh come on, if they don't like us they would have done something drastic by now."
     Astra and Sharna followed Telson into the compartment and the door closed silently behind them.
     "An elevator?" queried Telson.
     "It has to be."
     "It's not moving," Sharna pointed out.
     "All right, so it's not moving. Maybe we've overloaded it?"
     The door slid open again to show that the elevator had indeed moved because the scene revealed to the four was not the dish but a spacious circular chamber. Arranged around the perimeter of the chamber were a series of work stations in the form of comfortable swivel chairs in front of control consoles. There were a number of exits between the consoles. Positioned near each exit were more of the repair androids, their photonic lance tubes pointing at the floor. Darv could not help thinking that their position was no accident, it was as if the machines were guarding the exits.
     The floor and wall were covered with soft textiles in a pleasing selection of colours, and the ceiling was an unbroken surface of softly glowing green that provided the chamber's illumination.
     "It would seem," said Darv, looking around with great interest as he stepped out of the elevator, "that we have hit upon the nerve centre of whatever this place is."
     "That is correct, Darv," said a voice. "I am the control computer of Solaria D. Welcome."
     It was a female voice. Warm and friendly.
     Astra closed her eyes. "Please, no," she pleaded. "Not another guardian angel."
     "My name is Solaria, Astra," said the voice. "Why do you not know me? You are of Earth for you all have passed every test."
     Darv grinned at Astra's alarmed expression. "Don't worry, my lovely. I think I know what this place is. There's nothing to worry about."
     "Do you have news of Earth for me, Telson?" asked Solaria. "I have spent so many years wondering how she is faring."
     Telson turned slowly around, trying to locate the source of the gentle voice. "How do you know our names?" he demanded suspiciously.
     "I heard you using them. I watched your journey from your mothership and I listened to your radio communications."
     Solaria's honesty did nothing to ease Telson's hostile expression. "What is this place?"
     "I believe Darv knows."
     "It's an artificial sun," said Darv.
     "Was an artificial sun, Darv," Solaria corrected. "Solaria D was one of sixteen artificial suns that were constructed in orbit around Earth to pour down life-giving energy on its surface during Earth's journey to a new and safe sun. The size of each dish, the spread of their beams, and their orbital height above the Earth were balanced so that the cycle of the seasons, of life and death itself, would remain undisturbed during the great voyage."
     Telson's suspicions were aroused. "You're a freewill computer, Solaria?"
     "Yes." The single damming word was said without hesitation. As if sensing the impact of her reply, Solaria continued: "There was great opposition to the construction of freewill computers, but the task of maintaining all the systems of even one Solaria was beyond the capabilities of their crews. . . You must tell me about yourselves."
     "We were born in space on our mothership, Solaria," Darv replied. "Our ancestors were born on Earth but we have never seen it. When our mothership returned to the Earth's home solar system we discovered that the sun was unstable and that the Earth had vanished."
     "It is as I suspected," murmured Solaria.
     "Solaria. . ." began Sharna uncertainly. "Can you tell us where the Earth has gone?"
     "I'm sorry, Sharna, but I cannot for I do not know. Although I am a freewill computer, many of my systems have been damaged over the years by strange transmissions that I cannot account for. All I know is that the Earth is near. Perhaps within forty light-years."
     "But you must be able to tell us where it is!" Astra protested. "We've been looking for it for so long!"
     "I understand how you must feel, Astra, for I can see the anguish in your eyes." Solaria paused, as if she was trying to arrive at a decision. "But because you are humans, I do not have the right to deny you access to the library. It contains all the holograms and entertainments that were provided for my crew. Also there are all the logs and voice records of Solaria D. Everyday that passes is recorded even though the tracks have been silent ever since the Earth abandoned me."
     As Solaria spoke, a ball of silent blue light materialised in the air in the centre of the chamber. The four watched in silence as the ball moved towards one of the exits.
     "Follow the blue light," Solaria instructed, "and it will lead you to the library. Don't worry about the repair androids. They will not interfere."

        *  *  *  *
     Telson yawned and made room on the hologram replicator worktop for yet another batch of recording disks that Sharna placed before him. He groaned. "How many?"
     "About two-hundred."
     Telson groaned again and fed the first disk into the replicator slot. It was yet another engineer's report, meaningless columns of performance figures, the results of thousands of hours of monitoring Solaria's countless control systems. The four had been going through the vast library for six hours and had found nothing of interest. Darv and Astra were working at another replicator at the opposite end of the library. Two repair androids were standing motionless on either side of the entrance to the library, their photonic lances pointing at the floor.
     "Did you speak to Bran?" asked Telson, ejecting the hologram disk and inserting another.
     "Yes. I told him that we were working on a method of cutting up the dish."
     "Let me guess. He's a little mad at us?"
     "Demented is a better word. I think the angels would like to send an android-piloted shuttle after us but daren't in case there's another attack."
     Telson thought for a moment. "All right. If we don't find anything in six hours, we'll have to leave."
     Astra and Darv approached. Astra was carrying one disk. Her expression was one of triumph. She laid it carefully in front of Telson.
     "According to its index entry, it's a special broadcast made by Elkeran Six," she announced. "He was the President of Earth over a hundred thousand years ago."
     "Careful with it, Telson," Darv warned. "It looks brittle."
     Telson looked at the two-inch diameter disk with interest. If Astra was right, it was the oldest disk found so far. He ejected the disk the replicator was playing and carefully inserted Astra's disk. There was a faint hum as the replication field cleared. A picture appeared, the head and shoulders of a man facing the recorder. Age had obviously deteriorated the optical quality of the disk's surface because the image kept distorting and flicking from colour to monochrome. But the words the man spoke were clear enough:
     "Goodday fellow citizens of Earth. The purpose of this broadcast is to end the speculation about the fate of Solaria D. As you know, of the sixteen artificial suns orbiting the Earth, the erratic performance of Solaria D has been causing its engineering crew some concern. The last attempt to closedown its fusion reactor was a failure therefore it was necessary for me to order that Solaria D be expelled from its orbit.
     "I regret to say that several of its crew were killed when the traction beams were released. When our forefathers planned the departure of Earth from its solar system, their calculations allowed for the loss of ten Solarias during the voyage. Solaria D is our first failure and we have a mere forty years to go. We are nearing the end of the Earth's great journey and I am confident that we will experience no more difficulties during the remainder of our voyage to our new sun - Novita Six. . ."
     The recording ended and the replicator ejected the hologram disk.
     "Novita Six," repeated Darv, gazing thoughtfully at the dissolving replication field. He stiffened suddenly. What he said next occurred to the others almost before he started the sentence: "Do you realise that all we've got to do now is find Novita Six on the starmaps here and we've found Earth!"

     Part Five Sundeath.

     Telson ejected a hologram disk and added it to the stowage drawer of disks that he and Sharna had already examined. None of the few starmaps they had found made any mention of Novita Six. Darv and Astra had been gone thirty minutes on their exploring trip of the artificial sun -- watched every inch of the way by Solaria and her repair androids no doubt. He glanced across at Sharna who was sitting at her machine, industriously ploughing through several drawers of disks. She glanced up and shook her head.
     "Why are there so few star maps, Solaria?" asked Telson.
     "There were enough for my crew's purposes," answered the computer. "All the Solaria artificial suns were in orbit around the Earth therefore there was no need for a Solaria crew to concern themselves with astro-navigation. Where the Earth went, so we went. . . Until I became unsafe and was abandoned."
     Sharna looked up. Unlike the voices of the guardian angels on the Challenger it was impossible to tell where Solaria's voice was coming from. It was if she had the ability to make the air vibrate evenly throughout the artificial sun. "So you have no means of propulsion, Solaria?" she questioned.
     "No, Sharna." There was a pause. There was a slight edge to Solaria's voice when she spoke again. "As I have been as helpful as possible, I will be grateful if you would answer some questions for me. Your ship is of post- Solaric Empire design?"
     "Yes," Telson replied guardedly, catching Sharna's eye.
     "That is most interesting, Telson. Does it have a computer control system like me?"
     "It has two systems which I sincerely hope are not like you, Solaria. They are Angel One and Angel Two."
     "Ancillary Guardians of Environment and Life? That is even more interesting. Such systems are like me because they are freewill computers."
     Telson guessed what Sharna was thinking and decided not to give Solaria any more information. He was about to return to examining the hologram disks when Darv and Astra entered the library. Darv was carrying a small instrument by its shoulder strap and Astra was holding a small carrying case. Their expressions were pale and drawn.
     Sharna looked concerned. "What's the matter?"
     "Nothing," said Darv shortly. "Just a bit of a shock. Solaria will tell you about it I daresay. She's got quite a bit of explaining to do. The first thing we found was the communication room on the next level. All the radio equipment has been deliberately destroyed." He took the carrying case from Astra, opened it, and showed its contents to Telson and Sharna.
     Darv grinned. "What do think?"
     Telson took out one of the miniature hologram disks and examined it. It was unlabelled and looked in excellent condition.
     "We found them in the calibration room together with this," said Darv, placing the instrument on Telson's working area. "It's a portable hologram that those disks can be played on, or could if its power supply was working."
     "You will not be able to repair the portable replicator," stated Solaria. "And you will find its hologram disks of little interest. They were designed for engineers who wished to make memo recordings."
     "In that case I'm not interested," said Telson, pushing the machine aside and feeding another disk into the full-size replicator. "What concerns us is discovering the whereabouts of Novita Six. Surely, Solaria, somewhere in your memory there are starmaps for this sector of the galaxy?"
     "I'm sorry, Telson. Most of my facilities were assigned to routines to maintain the Solaria fusion reactor and to look after my crew. I've no idea where Novita Six is although I often heard the crew talking about it. I knew that it was the star that the people of Earth had selected as their new sun, and that is all."
     "Does your ignorance extend to what Astra and I found in the calibration room just now, Solaria?" asked Darv mildly.
     "Perhaps I should have warned you first," Solaria admitted. "Humans are so curious about everything."
     "Warned about what?" demanded Telson.
     "You better come and see for yourselves," was Darv's grim reply.

        *  *  *  *
     ""Chief Engineer Halsten -- commanding officer of Solaria D"," said Sharna, reading the legend that had been etched into the block of clear plastics that encapsulated the remains of what was just identifiable as the remains of a human being.
     "Sandrill Halsten," explained Solaria.
     "A man or a woman?" barked Telson.
     "A man."
     Sharna straightened up and stared at the twenty other slender blocks of clear plastics that were clipped to the calibration room's bulkhead, obscuring some of the instruments that had once monitored the performance of the artificial sun. Sealed and preserved within each block was a blackened, unrecognizable copse.
     At the far end of calibration room, two armed service androids stood motionless guard outside the door that, according to Darv, led to Solaria's central switching room.
     "A dreadful accident," said Solaria. "In a thousand years time my orbit around the star group will take me close enough to the nearest star to ensure a stable star-orbit burial for them."
     "What accident?" asked Darv, keeping a protective arm around Astra who was avoiding looking at the remains.
     "It was after I became unsafe and was ejected from Earth orbit," Solaria replied."They were a skeleton crew who had insisted on remaining on board after the evacuation in the hope that I could be repaired. They were working out on the dish when the tower released a burst of solar radiation."
     "You said that you're a freewill computer, Solaria?" queried Sharna.
     "Yes."
     "Then why is it that you remained active after this artificial sun was ejected from Earth orbit? Your central memory must have taken millions of hours to build. Even with a technology as advanced as Earth's, surely they would've wanted to keep you?"
     "For what other purpose, Sharna?"
     "Well. . . As a backup computer for the other Solarias. As it is you're useless aren't you, Solaria? A super intelligence looking after a derelict artifact -- unable to communicate with even a space shuttle when it approached you."
     Solaria's voice contained a hint of amusement when she replied. "You are right, of course, Sharna. And in view of the assistance I have given you, I would liked to be linked up with the communication systems on your shuttle."
     "Why?" asked Telson suspiciously. "Who do you wish to contact?"
     "Angel One and Angel Two," said Solaria lightly.

        *  *  *  *
     "Of course I understand the urgency of the situation, Bran," said Telson testily. "It's just that this artefact is made of a material that is going to be difficult to salvage. It's very tough."
     "What sort of material?" Bran's voice demanded.
     "Sharna's working on an analysis. Once we know more about it, we'll know how to deal with it. Out." Telson closed the channel and glowered at Sharna and Astra who were helping Darv connect up the portable hologram replicator to the shuttle's power supply. "We're going to have to teach that boy some manners," he muttered. "How's it going?"
     "It's working," said Darv. "It's a bit confined in here so I've set it to generate a very small replication field."
     "Play the unlabelled disk," said Telson.
     "Why?"
     "Isn't it obvious? Because it must the last one."
     Darv selected the unmarked disk and fed it into the replicator's slot. The space above the machine glowed and the sounds of a distant battle were heard: the blast and crash of plasma discharges; men screaming in pain. The head and shoulders of a uniformed man appeared. His fair hair was awry and he seemed to be crouching in a corner clutching a weapon that was out of sight. Pain had contorted his features.
     "This is Chief Engineer Sandrill Halsten," croaked the blond man. "Can you see and hear me, Mr President?"
     "Go ahead," said Elkeran. The president's voice was terse, as if expecting grave news.
     "I'm sorry, sir, but we've done everything we can."
     "You've got to stop her, Halsten! Smash her central switching room. Do whatever you have to but, in the name of Earth, stop her!"
     Solaria's voice burst in. Not the gentle voice that the four had heard so far, but a demented voice; a voice crazed with the lust for power: "Total control, President Elkeran! Total control over the other solaria computers or I shrivel your largest city in two minutes!"
     The sounds of the battle drew nearer. "This time she's not bluffing," Halsten panted. "We've wrecked all the communication equipment so that she can't contact the other freewill computers, but she's mobilized all the welding androids into two battle groups -- one guarding the control room and the other one fighting us."
     A plasma flame bolt smashed into the bulkhead above Halsten's head, showering him with sparks and setting fire to his uniform.
     "We will have to switch off the traction beams and release her from Earth orbit," Elkeran decided. "First we'll send up a personnel ferry to evacuate you and your crew--'
     "Cut her loose now!" Halsten snarled, ignoring the flames that were taking hold of his tunic. "What's left of my crew will send Solaria D on a stardive course if we can get back into the control room -- but you must release the beams now!"
     The next flame bolt found its target. The four watched in horrified silence as they saw Halsten's face dissolve like wax under the impact. The replication field went blank a second later.
     At that moment an attack started. It was more powerful than all the other transmissions that the four had experienced so far. Within seconds the strange music rose to a shrill, nerve-grating whine.
     Telson jumped to his feet. "Come on! Before it's over! Sharna - see if you can get a direction-finding bearing on the source of the attack!"

        *  *  *  *
     The two androids guarding the door to Solaria's central switching room were paralysed by the attack and offered no resistance when Telson and Darv snatched away their welding tubes from their weakened manipulators and turned them on the door. The jets of plasma ate into the strange steel, turning its surface red, and then white.
     "You cannot enter," Solaria protested weakly. "It is forbidden. . . My androids. . . My androids. . ."
     The door collapsed just as the energy charges in the rods were virtually exhausted. Telson was first through the door. Without hesitation, both men levelled their weapons at the organic intelligence that was floating in a clear-sided nutrient tank like a bloated jellyfish and opened fire. There was an anguished scream. For a second it seemed that the grotesque entity was trying to climb out of the tank. A severed nerve tendril fell from a bulkhead and thrashed dementedly on the floor for a few seconds. Darv directed the rapidly weakening stream of plasma from his weapon on the nerve. It blackened, coiled itself up like a spring, and then slowly relaxed. The two men stopped firing, their weapon capsules spent.
     "There's one more thing we have to do," said Telson, surveying the mass of blackened, twitching nerve tissue that had once been an organic computer. "We've got to destroy the library. Bran and the guardian angels must never find out about Novita Six."
     Darv nodded in agreement. He turned to leave the central switching room and stared at the twenty preserved copses of Solaria's crew. "Actually, Telson, there's two things we've got to do."
     The harsh whine of the transmission gradually diminished and reverted to the more usual reverberating music. Even that died away after a few seconds. The attack had lasted ten minutes. The longest so far and certainly the most intense.

        *  *  *  *
     The portable thruster fired when Darv touched the control key. The lines connecting the string of twenty encapsulated corpses tightened and the bizarre procession moved away from the shuttle, heading towards the nearest star which, at a distance of one light year, was near enough for it to appear as a tiny glowing disk instead of the more usual point of light.
     It was an hour since the shuttle had left Solaria D. Darv and Astra were wearing mobility suits and had worked for thirty minutes in the shuttle stowage bay, linking together the bodies of Solaria D's crew. Both were breathing heavily from their exertions: although the twenty blocks of plastic had been weightless, they had still possessed mass.
     They watched the line of corpses in silence for a few moments.
     "I wonder if that star's Novita Six," said Astra over her mobility suit's radio.
     "It could be. It's where Sharna thinks that the attack originated from."
     "Earth's new sun. . ." said Astra wistfully. "If it is, they're going home."
     "It's a nice thought," Darv replied.

        *  *  *  *
     Angel One was the first to recover from the effects of the devastating attack. Regenerating all her primary foreground task levels took thirty minutes but the more intricate repairs to her thousands of damaged background task levels took three hours. Angel Two had suffered worse damage and there was a period of six hours during which he was forced to reassign several thousand monitoring tasks to Angel One while his wrecked levels were regenerated.
     The most alarming aspect of this latest and most severe of all the attacks was that the delicate neural links between the two angels and their Android Surgeon-General Kraken in command of the main control room had been destroyed. The angels had no means of determining what damage had been caused to the giant android's logic functions and, until the neural links between them and the main control room were renewed, they had no control over the Challenger's photonic main drive and guidance systems.

        *  *  *  *
     The shuttle was poised outside the Challenger excursion terminal, waiting for the doors to open, when Sharna said: "I'm sorry, Astra, but there must've been a mistake in navigational figures. The Challenger's scoops are still furled so she obviously hasn't used her photonic drive and yet she's definitely not in the exact position that she ought to be in."
     "Well it hasn't prevented us from finding our way back to her," Telson observed. "How much longer do we have to wait until they open the doors?"
     Darv chuckled. "What's the betting that the last attack caused considerable damage to Angel One and Two?"

        *  *  *  *
     "I tell you there was nothing on Solaria D!" said Telson angrily. "Searching for clues as to the Earth's whereabouts was the first thing we did."
     "Why should I believe you?" asked Bran sardonically. His face was pale and drawn and his eyes hard and resentful.
     "You'll see for yourself when the Challenger catches up with Solaria D," said Telson. He glanced at Elka and Sharna who using the observatory's main optical telescope and turned to face Bran again. "I presume that we are going after Solaria?"
     "When I've decided," said Bran coldly.
     "Not on this course, we're not," said Sharna.
     "I said -- when I've decided," Bran repeated, raising his voice.
     "Please find Solaria for me, Sharna," begged Elka. "I'm useless with the telescope and Angel Two's being quirky again --he's not answering when I call him."
     Bran gave Elka an angry look.
     "So what's wrong with our beloved angels?" asked Telson. He spoke casually -- deliberately injecting a disinterested tone into his voice.
     "What should be wrong with us, Telson?" inquired Angel One's voice.
     "You've still not explained why we had to wait fifteen minutes outside in the shuttle before you opened the excursion terminal doors," said Telson pointedly.
     "We do not have to explain anything to you, Telson. You are no longer the Challenger's commander."
     "That's Solaria," said Sharna, making a fine adjustment to the telescope to sharpen the image of the artificial sun that had appeared on the repeater screens. She frowned and checked the telescope's settings. "But it's not in the position it ought to be in."
     "Well you can't blame Astra's calculations this time," observed Telson.
     "What are you talking about?" demanded Bran.
     "Hold on," said Sharna, touching out the controls that repositioned the huge telescope. "The graviscope's showing an anomaly."
     The telescope's servo-motors drove the telescope smoothly around a few degrees on its tracks until the objective lens was centred on the new position that Sharna had loaded. She studied her monitor screen for a second and looked up the nearest angels' voice terminal.
     "I take it that you Angel Two are maintaining a continuous surveillance of our immediate surroundings, Angel One?" she asked.
     "It is for me to ask questions of the angels," said Bran angrily. "I'm the commander of the Challenger!"
     "So you keep telling us," said Sharna wearily. "Okay then, Bran, you ask the question."
     Telson looked questioningly at Sharna. "What's the matter?"
     "I am about to transfer all my facilities to other functions," said Angel One. "There will shortly be a period in the observatory when I will be unable to respond to any questions."
     Bran was momentarily stunned by the extraordinary announcement. It was a second before he regained his self-control. "Before you go, One. Has a full surveillance been maintained of the immediate space around the ship?"
     "There would appear to be a gravitational anomaly beyond the Solaria artificial sun," Angel One admitted. "It is of no consequence. I must go now."
     "Too damn right there's an anomaly," said Sharna fiercely. "No wonder poor Astra couldn't make her navigational figures work out." She switched on the repeater screens so that everyone could see what it was that she had discovered.
     Telson stared at the screen. At first he could see nothing unusual. There were the usual myriads of stars covering the picture, with Solaria just visible on the edge of the screen. And then he realised that there was a patch of space in the exact centre of the screen where no stars were shining. He stared harder and his heart sank when he saw that the starless patch was circular in shape and that it had a faint halo of light. There was only one thing the phenomenon could be. He caught Sharna's eye and nodded.
     "What is it?" asked Elka, who had also noticed the circle of darkness. "Why aren't there any stars there? Angel One -- why aren't there any stars in the centre of the screen?"
     There was no answer. Elka looked frightened.
     "Because it's a black hole -- possibly a collapsed dwarf star," said Sharna savagely. "Whatever it is, Solaria is accelerating towards it, and we're following Solaria."

     Part Six Supermass.

     As much as Angel One disliked having to reveal the weakened state of herself and Angel Two, she felt that she had no choice. Abandoning the observatory was regrettable but could not be helped.
     Angel Two had regenerated sufficient observatory levels to identify the source of the attacks as definitely originating from the nearby star group. The problem was that the hurried regeneration may have been faulty because the data he was obtaining showed that the gravitational anomaly was also a source of the attacks. It was data that did not make sense therefore it was decided between them that Angel Two should be closed down completely for a temporary period during regeneration while Angel One maintained what control she could over the ship.
     Despite the urgency of re-establishing control over Kraken, it was important that some of the available levels were concentrated on monitoring Darv's behaviour. Angel One switched through all the undamaged monitoring facilities that could be spared and located Darv and Astra making their way to their quarters.

        *  *  *  *
     "Hallo, Tidy," said Darv cheerfully as he and Astra entered their cabin. "We're back."
     The android groaned. "Why is it that all humans appear to be programmed to state the obvious?"
     Astra smiled. "Didn't you wonder what had happened to us?"
     "I had hoped that you had all met with a fate that would have kept you away from my nice, tidy cabins. I suppose you want them back so that you can mess them up?"
     "Did any service androids try to mend the damaged tracks while we were gone?" asked Darv.
     "I had them trying to get in every day," the android complained. "But they always left when they saw me."
     "And you stayed in here all the time?"
     "Those were your orders. Although I often ask myself why I bother to obey them." The android added on an accusing note: "But I was switched off again."
     "What happened?"
     "You want to gloat I suppose?"
     "I promise you that we don't," said Astra. "Just tell us what happened."
     "It was like all the other times only worse," said Tidy disdainfully. "Froze up, I did. Froze right up. I was having an argument with one of the service units at the time when all of a sudden -- zonk."
     "Zonk?" said Darv, trying hard to keep a straight face.
     "Zonk," Tidy affirmed. "It lasted longer than the last time, and it took me longer to recover afterwards. It's a disgrace the way I'm treated. A disgrace."
     Darv pressed Tidy for more details. "Did the other android take a long time to recover?"
     "Yes. I had to put up with it cluttering the place up for two hours. It made the place look dreadfully untidy, it did."
     Darv was lost in thought for a moment. He moved into the corridor and called out to Angel Two. After a delay, Angel One answered:
     "Yes, Darv?"
     "I called Angel Two."
     Another delay, then: "Two is extremely busy at the moment."
     Darv raised an eyebrow and winked at Astra who was watching him from the cabin. "Really, One? But there was a time when it was impossible to overload a guardian angel and there was no delay in your replies. What's gone wrong for you both?"
     Several seconds passed before Angel One answered. "It would be best if you both reported to the observatory," Angel One answered.
     It was on the way to the observatory, that Darv and Astra discovered that Angel One had ceased functioning.
     "Being organic, I suppose they're capable of self-repair?" queried Astra.
     "Yes."
     Astra looked thoughtful. "Obviously they concentrated on repairs to the monitoring levels around our quarters first."
     "What's on your mind, my lovely?"
     They stopped walking when Astra put her lips close to Darv's ear. "What are our chances of regaining control of the ship?" she whispered.
     Darv grinned. "You and I are beginning to think alike. The trouble is that Bran is definitely armed, so is our daughter for all we know, but we're not."

        *  *  *  *
     Telson's face was pale as he turned away from the telescope's repeater screen and stared at Bran. "Do you have any idea what a black hole is?"
     Bran returned his father's stare, his eyes cold and expressionless. "A hypothetical region of space resulting from the gravitational collapse of a star following the exhaustion of its nuclear fuel. A supermass. So immense that sometimes not even light can escape its gravity." He gave a ghost of a smile. "Educational androids can be more efficient than parents, Telson."
     Darv and Astra entered the observatory. Telson gestured to the repeater screen for their benefit and said to Bran: "You ought to take a close look as well."
     "I've observed the phenomenon before," said Bran.
     "At a range of one million miles?" said Telson angrily. "Take a close look at it, Bran, and then let's have a hypothetical discussion about your monumental carelessness in letting the ship get so close to one."
     Bran looked bored. His hand dropped to his PD weapon. "All four of you will return to your quarters immediately."
     "For once you're going to listen to me," said Telson angrily. "I don't care if you do fire because I find that thing out there a damn sight more frightening than any PD weapon. Obviously you know nothing about commanding this ship otherwise you would know that standard control room procedures require that the ship does not approach even a Class One black hole closer than one light-week. We're a million miles from that black hole. What class is it, Sharna?"
     "Class Five as near as I can judge."
     Telson nodded. "Tell him the clearance, Astra."
     Astra tore her eyes away from the sinister circle of blackness in the centre of the main screen. "It's one light-week for every point on the scale," she answered. "If that thing is a Class Five, then the Challenger should not be navigated within five light-weeks of it."
     "So," continued Telson. "I suggest that you and Elka go to the main control room now, reorientate the ship, and apply maximum photonic thrust."
     Elka giggled.
     "I'm glad you find it amusing," Telson commented acidly.
     "Oh it's not that," said Elka brightly. "It's just that we--'
     "Elka," Bran interrupted warningly.
     "If that spooky blotch is dangerous, then maybe they ought to be told," said Elka, smiling inanely around at everyone.
     "We should say nothing," said Bran coldly.
     Elka's smile vanished. There was a sudden and uncharacteristic hard look in her eyes. She said quietly: "I will say whatever I wish to say, Bran."
     Bran tensed. For a moment it looked as if his customary iciness was about to desert him. He was about to say something and then seemed to change his mind. He shrugged.
     "You see, people," said Elka. "It's like this. We don't actually know where the main control room is."
     The four stared disbelievingly at her.
     "We've heard of it, of course. We knew that the angels had moved it or something when they rebuilt the ship, but they always said that we needn't bother about it. I mean - well - they look after everything, don't they?"
     "Until now," observed Telson. He looked at Elka and Bran in turn. "Don't you have any idea at all where the main control room is?"
     Their silence answered his question.
     "That can only mean that it's under android control."
     "Does it matter?" said Bran disinterestedly.
     "It matters a lot," said Sharna. "The original builders of this ship designed the main control room for operation by a minimum of four people because they didn't trust freewill computers. Using surgical androids to man the control room was our idea, but only for short periods, and certainly not for long periods with people on board. Surgical androids are good, but not that good." Sharna paused and nodded to the nearest voice terminal. "And right now it would seem that the angels are useless."
     "Why?" asked Elka.
     "Those noises are destroying them faster than they can recover," Telson replied. "That's the real reason why they want to increase the thickness of the Challenger's skin. It's their desperate hope that it'll protect them." He regarded Bran steadily and added: "All that talk about improving the meteoroid shielding is nonsense that only a child would swallow."
     Bran ignored Telson and looked up at a voice terminal. "Angel One!" he called out.
     There was no reply.
     "Angel One! Angel Two! This is Bran. Will you answer please. . ."
     Again silence. Bran called several more times but there was still no answer. It took a considerable amount of will power on his part to assume an unconcerned expression as he gazed for a few seconds at the black hole. Telson wasn't fooled.
     "How much is that thing affecting us?" asked Bran.
     "This is the observatory -- these instruments are not navigation instruments like those in the main control room," said Sharna. "Without the angels' help, getting exact figures will be impossible, but I daresay Astra and I could work out some rough estimates. But if you want hard information for evasive action, then we'd better find the main control room and find it fast."
     Another attack started just as she finished speaking.

        *  *  *  *
     Stage by stage, Angel One was forced to abandon control over the Challenger in order to maintain her essential regeneration facilities and those belonging to Angel Two. Monitoring levels were closed down and most of the normal day-to-day background tasks such as the routine reprogramming of the service androids were suspended.
     Repeated attempts to contact Android Surgeon-General Kraken commanding the main control room proved fruitless. The mighty android had been designed to operate alone for long periods, but it was more than possible that the attacks had damaged his facilities for logical behaviour.

       *  *  *  * Darv swore when he rounded the corner of the corridor and saw the ugly steel bulkhead that blocked the passage.
     "Another dead end down here," he called out to Telson and Bran as they joined him.
     "Give me the radio collar," said Telson curtly to Bran. The youth opened his mouth to protest but Telson cut him short. "Don't argue, Bran! Give me the collar!"
     Bran unclipped the collar from around his neck and handed it Telson without comment. The sudden loss of his mentors, the guardian angels, had undermined his self-confidence and arrogance to a certain extent.
     "Anything, Astra?" said Telson into the radio collar.
     "Nothing to report on our level," Astra replied. "There doesn't seem to be any undefined space that could accommodate the control room. Elka's checking the last corridor on our level now."
     Darv knelt down in front of the bulkhead and ran his hands over the rough steel.
     "We've had no luck either," said Telson. "Nothing but dead ends. Let me know before you move to another level. Out."
     Bran held out his hand for the collar. For a moment Telson considered not returning it but decided that it would be best not to goad his son too far. Not just yet.
     "Thank you, Telson," said Bran, snapping the radio collar back into place. "Tell me, what if we do find the control room?"
     "Then we take control of the ship, of course."
     "I control the ship, Telson. Let us be quiet clear on that point."
     This was too much for Telson's short fuse. "Now you listen to me--'
     "I think the sensible view is that we concentrate on finding the control room," Bran interrupted, raising his voice.
     "I think we've found it," said Darv suddenly.
     The two protagonists broke off and stared down at Darv who was still on his knees before the bulkhead.
     "We're pretty certain that this was the level that the old control room used to be on," said Darv. "Supposing the angels didn't move it but merely relocated all the surrounding approaches to it and sealed it off with these bulkheads? That would be much easier from the engineering point of view." He gave Telson and Bran a broad grin and gestured at the bulkhead. "So if we were to try moving in a straight line instead of following the corridors. . ."
     Telson broke the brief silence that followed. "Bran, give me your PD weapon."
     Bran laughed.
     "All right then," said Telson, pointing at the bulkhead. "You do it. Cut a hole through that and no arguments please."
     For a moment it looked as if Bran was about to lose his temper. His face went white and he turned to face Telson. At that moment Darv sprang and twisted both Bran's arms behind his back. The momentum of his lunge slammed the youth against the side of the corridor. He gave a gasp of pain.
     "Lesson one," breathed Darv, holding Bran pinioned against the wall. "Never turn your back on the enemy."
     Telson yanked Bran's PD weapon from its holster and levelled the weapon at his son. "Okay, Darv. Let him go."
     Bran glowered resentfully at both men. Telson lowered the PD weapon. He seemed uncertain what to do next. And then, to Darv's amazement, he reversed the weapon and held it out to Bran.
     "Burn a hole through that bulkhead please, son."
     Bran took the weapon without a murmur and pointed it at the bulkhead. He opened fire as soon as Darv and Telson had moved clear. He adjusted the angle of the streaming plasma jet to a narrow beam so that it sank rapidly into the steel. Flames, sparks and globules of white-hot metal spat from the channel cut by the weapon as he moved it slowly, describing a circle. No one spoke during the five minutes that it took Bran to cut a circle large enough for a man to crawl through. He stopped the burn as soon as the jet had reached its starting point. Darv placed his foot in the centre of the circle and pushed. The steel disc fell inwards with a resounding clang that echoed along the corridor.
     Telson wriggled through the opening first. "Mind the edges, they're hot," he warned as Bran and Darv followed him.
     "Well," said Darv, taking stock of their new surroundings. "This looks familiar."
     "Why?" asked Bran, looking curiously along the corridor.
     "Because this is the approach corridor to the main control room," said Telson drily. "Good thinking, Darv."
     "It just goes to show how useful it can be to have a genius like me around."
     "The radio please, Bran," requested Telson.
     Bran handed over the radio collar without argument. "Now what?" he said uncertainly when Telson had notified Sharna and Elka of their find.
     Telson smiled. "A breakthrough, Darv. Bran is asking for advice."
     Before Darv and Telson had a chance to react, Bran levelled his PD weapon and loosed off a blast between the two men. They wheeled round in time to see the bolt of plasma hit the small, black android that had that appeared at the far end of the corridor. The blast fired by the android went wide and hit the ceiling above where the trio were standing. They threw themselves flat just as another android appeared. It was clutching a PD weapon in its manipulator. It raised the weapon to the firing position when a second blast from Bran smashed into its tracks. The unbalanced machine veered into a bulkhead and then spun round on the spot until Bran finished it off with a well-placed shot in the chest that caused its total disintegration.
     "Wouldn't it be nice," said Darv. "If for once , just for once, someone was pleased to see us."
     Bran jumped to his feet and, ignoring Telson's and Darv's warning shouts, went to investigate the two destroyed machines. He was turning over the wreckage when Telson and Darv joined him.
     "You're quite handy with a PD weapon, Bran," Telson observed, keeping a wary eye on the end of the corridor where the aggressive little androids had first appeared.
     "Just make sure you don't forget it," warned Bran. "Where have these come from? I've never seen androids like them before."
     Darv picked up the shattered remains of a manipulator. "Definitely made in the Challenger's android production plant. I wonder why it took an immediate dislike to us?"
     "With six PD manipulators? That's all it is designed for," Telson commented.
     "Does it's design philosophy remind you of anything, Telson?" inquired Darv.
     "Fagor?"
     "A miniature version of him."
     Bran frowned. "What are you two talking about?"
     "An unpleasant android we once encountered before you were born," answered Telson.
     "So why should our beloved guardian angels fancy having a few little Fagors around?"
     Six more of the warlike androids appeared at the far end of the corridor.
     "You know what I think?" said Telson.
     "That they've come to surrender to us?" asked Darv.
     "That we should consider withdrawing in good order."
     "A triumphant retreat before an enemy advancing in utter disorder?"
     "Something like that," said Telson.

        *  *  *  *
     "Fagors?" said Astra in surprise when everyone had reassembled in the observatory.
     "Six of them," Telson confirmed. "Plus the two that Bran got. He's rather good with a PD weapon."
     "Who's Fagor?" asked Elka. "He sounds fun."
     "You wouldn't say that if you'd ever met him," commented Astra. "So it looks like you got near to the control room?"
     "Well it certainly looked like the old approach corridor," said Telson. He looked pointedly at Bran. "It's obvious why it's so heavily guarded. The angels must've decided that humans should never be allowed near the main control room again. If we're to regain control of it, then you'll have to let us have our PD weapons back."
     Bran stared hard at Telson for a second and then gave a sardonic smile before shaking his head.
     "It's our only chance, damn you!"
     "The angels will be back," stated Bran. "They've never deserted us." He added pointedly: "Which is more than can be said for our parents."
     "Telson," Sharna called out from where she was sitting at the telescope's control console. "Take a look at your repeater screen."
     "My repeater screen!" said Bran indignantly.
     "Course deviation is now four eight one and increasing."
     Elka looked worriedly at the sinister black hole that was displayed on all the repeater screens. "I say, people. It does look a bit unfriendly."
     "There's no such thing as a friendly black hole," Telson observed caustically.
     "There's something very odd about it," said Sharna, puzzled. "I'm no expert on black holes but the X-ray emissions from colliding particles in its vicinity are not as high as they should be. The gravitational readings say that its a Class Five and yet the X-ray readings say that it's not even massive enough to be even considered a Class One."
     "But it's still deflecting us from our course?" demanded Bran.
     "No," Sharna replied. "There is no deflection now. We're heading straight for it."
     Bran's self-possession seemed to desert him. He looked worried. "What will happen to us?"
     Telson shrugged. "A cubic inch of black hole matter can possess a mass of several thousand tonnes or even a million tonnes. Your guess is as good as mine. But I daresay that whatever happens will be quick and painless." He paused for a moment to let his words sink in. "So how about those PD weapons, Bran?"

        *  *  *  *
     George regarded the gaping hole that had been cut for him in the bulkhead with considerable suspicion. "Now what?" grated from his crude speech synthesizer.
     Darv paused before replying because he thought he felt a faint breeze on his face. Apart from the air convection currents that were encountered in the farm galleries and the water reservoir, draughts were unknown on the Challenger.
     "Well?" George demanded.
     "Through you go, George," Darv instructed. "Then turn left, and then stop."
     The big agricultural android lurched through the opening and swung to the left on its broad tracks. It stopped, it's bulk filling the corridor so that there was only a few inches clearance on both sides.
     "Fine, George," complimented Darv. "You're next, Tidy. Wait behind George."
     The little android turned to Telson who was holding up a wet thumb and looking puzzled. "Commander. This is an official complaint. I'm not designed for waging war. Wars are untidy. They make a mess everywhere."
     "Which you can clear up afterwards," said Telson. He took a threatening step towards the android.
     "All right. All right. No need to get aggressive," said the android hastily. It took the offered PD weapon from Bran and scuttled through the hole, taking up its position behind George. "Just so long as my official complaint has been registered."
     "Why do you put up with that android?" asked Bran.
     "It's a question I'm always asking myself," said Telson. "What's that noise?"
     Bran tilted his head on one side and listened to faint, rushing sound. "I don't know," he admitted.
     "I felt a draught just now," said Darv. "There it is again."
     This time all three of the men felt the stirring of the atmosphere. The erratic draught suddenly became a steady breeze that whined along the corridor.
     Telson fingered his radio collar. "Sharna. We're getting a breeze. Any idea what could be causing it?"
     "Elka's just reported the same thing," Sharna replied. "It could be differential gravitational effects that the black hole's having on the atmosphere. We'll check it out."
     "How are things in the observatory?"
     "Astra's still checking the calculations. She says that you've got to get into the room in forty-five minutes at the latest otherwise the photonic drive's thrust won't be able to counter the pull of the black hole."
     Telson swore. "But that's thirty minutes off her last estimate."
     "Sorry, Telson. Good luck'
     Telson glanced at Darv and Bran. "You heard that?"
     They nodded.
     Telson pulled his PD weapon from its holster. "So what are we waiting for?" He stepped through the hole and took up a crouching position behind George. Bran and Darv fell in beside him.
     "Okay, George," said Telson. "Forward to the end of the corridor and turn right. Just keep going if androids start shooting at you."
     "Humans stupid," grumbled the big machine as it lumbered forward. "Androids don't shoot at androids."
     Two androids appeared at the far end of the corridor and immediately set about proving just how wrong George could be. The blasts from their PD weapons smashed into the agricultural unit's armoured track guards, showering clouds of sparks everywhere and producing a volley of complaints from George. Darv and Telson instinctively ducked but Bran and Tidy straightened up and returned the fire with uncanny accuracy. The two androids disintegrated.
     "Mine!" said Tidy triumphantly.
     "You got one and I got the other," Bran corrected.
     "They were mine!" howled Tidy. "I don't mind you arguing with your father, but you would do well to remember that I brought you up, young man. I used to clear up all the disgusting messes you used to make and I--'
     "Will the pair of you stop arguing!" Telson roared as another salvo of plasma discharge meteored into George.
     Above the racket, Telson was uncomfortably aware that the sound of rushing air was noticeably louder and that the breeze was strengthening.
     Darv opened fire on the five androids that had appeared. He disabled one and missed the others. At the speed they were moving, they would have overrun George had not Tidy, Bran and Telson opened up with a murderous barrage that completely obliterated the four remaining machines.
     Darv spotted the damaged android struggling back on damaged tracks towards the far end of the corridor. "Now, Tidy!" he yelled. "Grab that one!"
     Tidy used his manipulators to vault over George's bulk. He scooted along the corridor, grabbed the damaged android and wrenched off those of its manipulators that had been fitted with PD weapons. He dragged it backwards, clambered over George and dumped the mangled machine beside the others.
     "Android Surgeon-General Kraken will destroy you for this!" it protested as it clattered to the floor.
     Darv yanked the machine upright so that it was standing on its wrecked tracks. "Who's Android Surgeon-General Kraken? Talk, little one, or I'll tear out your organics."
     Like all high grade androids, the machine possessed a self-preservation instinct, therefore it talked: "Surgeon General Kraken is all-powerful."
     "He's your commander?" demanded Telson.
     "Of course."
     "Where is he?"
     "The mighty Android Surgeon-General Kraken is everywhere." the machine answered defiantly. "He is the commander of the main control room. Even now, he is planning your eventual destruction."
     The android's last words were snatched away by the wind that had risen to a howl and was plucking dementedly at everyone's clothing.
     "What the hell's happening?" yelled Darv.
     George chose that moment to throw his followers into a state of near-panic by stopping and going into reverse. His tracks crunched over the captured android, effectively silencing its shrill barrage of protest.
     "You crazy android!" Tidy yelled. "You nearly ran me over!"
     "George! You're supposed to keep moving forward!" Telson shouted, imitating the backward hops of the others to prevent himself from being flattened under the big agricultural machine.
     "Passage too narrow for George," the android announced, his voice barely audible above the hurricane-like howl of the wind. "Can't go any further. No good expecting miracles from androids."
     "Then stop reversing, you brainless machine!" Bran screamed.
     George stopped just as some more androids renewed the assault. Darv and Bran kept them busy while Telson contacted Sharna in the observatory.
     "Sharna! What the hell's happening? It's blowing a gale down here!"
     "There's been a mistake in our figures, Telson," Sharna cried despairingly. "Either that or its gravitational pull isn't consistent. We've no hope of escaping the black hole now at this acceleration rate'
     Despite the enormity of Sharna's words, Telson hardly heard them because, as he stared along the corridor, it seemed that something was playing insidious tricks with his eyes: the corridor was becoming shorter. The voices of his companions were suddenly distorted -- not by the roar of the wind for it was as if their voices were becoming compressed, just as the corridor was. He vaguely heard someone shouting about their eyes but it was impossible to determine whose voice it was. The colours around him were changing -- everything was turning red: the drab sides of corridor, the frightened faces of his companions who had stopped firing -- even his own hands. He tried to speak but the only sound he could make was an unintelligible high-pitched squeal. There were more of the strange squeals that he realised were coming from Darv and Bran. The reddening became an opaque crimson fog that blanked out everything. The noise numbed his senses to the point where he no longer knew which way was up and which was down. His groping hands encountered something hard, it could have been George, or the walls, or the floor, there was no way of telling which. The noise was two screaming drills of blinding agony boring into his skull.
     Suddenly there was a merciful silence and blackness.

        *  *  *  *
     Telson had no way of telling how long he had been floating in the twilight world that straddled the threshold between unconsciousness and reality. For a while the sensations of wakefulness were stealing up on him and then retreating back into the darkness, and he observed them all with detached disinterest: the feel of something hard that his head was resting on; a dull ache in his joints; a cool draught of air playing on his face. He opened his eyes and experimented with focussing them on whatever was above his head. There was nothing above his head, no lights, no visual clues for his eyes and brain to latch on to. Just blackness.
     Full consciousness came quite suddenly as if it had been waiting on the sidelines for an opportunity to strike with the full force of reason and perception.
     He sat up and stared at the bodies laid out in a neat row in the semi- darkness. The row included himself. They were all there: Darv, Sharna, Astra, and Bran and Elka. Darv sat up, nursed his head, and groaned.
     It was then that Telson noticed the dimly-lit scale model of the Challenger a little way off. It was a perfect model in every respect -- even down to the fine detail on the heat dissipation fins around the photonic drive outlet ports. As he stared at it, there was a slow dawning that he wasn't looking at a model -- it was the Challenger. Nor was it close to but a some way off. The sight of the seven-mile long starship resting on what appeared to be complex system of massive cradles was so incredible, so impossible to grasp, that Telson's brain refused to accept the evidence of his eyes. A spiral staircase circled around one of the massive tubular uprights that formed part of the cradle system. The steps ended level with the open doors of the Challenger's excursion terminal. There were ant-like human figures on the steps and it was possible to discern a freight lift in the form of an apparently unsupported pallet moving up the outside of a tubular column.
     He must have made a sound because Darv looked up and caught sight of the distant bulk of the Challenger.
     "I don't believe it," said Darv weakly. "Someone tell me it's not true."
     "It's true right enough," said Telson grimly. He stared around and realised that the Challenger wasn't alone. Scattered at regular intervals on the dark plain that stretched into infinity was every type of spacecraft imaginable and a few that it wasn't possible to imagine. Some were little more than twisted heaps of wreckage and others, the Challenger included, appeared to be intact. They ranged from craft with the same thrust transfer efficient cylindrical shape as the Challenger to those that resembled flattened dishes. There was even one in the far distance that looked as if it was bigger than the Challenger.
     "I pass out plunging into a black hole and I come to in celestial junk yard," observed Sharna. "Someone tell me I'm not dreaming."
     Astra was the next to regain consciousness followed by Elka and Bran.
     Telson silenced the outburst of chatter by raising his hand. Everyone fell silent when they saw the approaching light. There were ten grey uniformed men standing on the strange railed platform that was heading towards them. There was no sound from the vehicle, not even the faint hum of a stabilizing gyroscope. The platform stopped within a few yards of the hypnotised group and the safety rail sank neatly into the vehicle's floor, enabling nine of the men to step down and surround the mystified new arrivals.
     There was nothing particularly sinister about the men, they did not appear to be armed, but Astra found herself gripping Darv's arm with animal-like strength.
     There was one man left on the platform. He was aged about 35 and was slightly taller than his companions. When he spoke, his voice was soft and reassuring.
     "I've been listening to you. I must congratulate you on your consummate skill with our language." Despite his gentle voice, the man's clear tones echoed around the vast interior. The words "our language" were whispered repetitively as they decayed away into silence.
     "I'm sorry. . ." said Telson, groping for words as he recovered from the shock of the man's clearly modulated voice.
     "Are you recovered?" the man inquired.
     "Well. . . Yes."
     The man smiled. "You must forgive me. My name is Theros. I am the chief engineer of the Spaceguard."
     They stared at the man in silence. Telson eventually found the necessary words for a coherent sentence.
     "Where are we, Theros? What is this place?"
     Theros chuckled. "They always ask that. In their own tongues, of course - those that evolution has given tongues."
     "Who?" asked Darv.
     "Aliens, of course. In your case it is a pleasure to have visitors who have decided to master our language. We look upon them with great delight and, at the same time, with great caution. It is not an easy language."
     "What is this place?" asked Telson, wondering if the whole thing was another of the angels' hallucinations.
     "It is of a much more advanced technology than the technology that built your ship, my friends. Your ship must be one of the oldest that we have ever tractioned into the Spaceguard. We are the equivalent of the walls they used to build around cities on Earth to keep out enemies. We make certain that aliens passing through this sector towards Earth go no further."
     "So this isn't a black hole?" queried Telson.
     Theros chuckled again. "It looks like one, doesn't it? Try as they can to avoid us, no ship can ever escape. We traction them all in."
     "Then we can continue on our way to Earth?" said Darv eagerly.
     Theros shook his head in what seemed to be genuine sorrow. "Sadly, no."
     "But we're descended from Earth people, Theros," Darv stressed.
     "As we all are here," Theros replied. He raised his eyes to the Challenger. "We have examined your records. Like you, we were not born on Earth but here on the Spaceguard. Our great calling is to devote our lives to the protection of the Earth; our great sacrifice is to do so without ever seeing it."
     "You must allow us to continue on our way to our home," stated Telson.
     "No."
     "You accept that we're Earth descendants, Theros?"
     "Yes. The problem is not you but your computers. There was a time when every ship was built with freewill computers like yours. Computers with remarkable abilities but whose automatic self-preservation systems degenerated into delusions of grandeur, desires to conquer and rule everything, including their makers. Some of those computers tried to launch major offensives against the Earth. That's why this Spaceguard was built. There may be others. Our other task is stop the aliens, of course."
     Darv frowned. "What aliens?"
     "Only the hostile ones. There are some who are peaceful. Only a few. The others we destroy."
     "You can destroy our computers with the greatest pleasure," said Telson.
     Bran looked as if he was about to say something. Theros gave the youth a searching look before answering Telson's comment. "We shall. We had to take steps to prevent the Solaria computer forming an alliance with your computers. Solaria was a case of a freewill computer that was harmless because all her communication systems had been destroyed. She had been drifting in this sector ever since the Earth abandoned her. We saw little point in wasting energy disintegrating her but we were most concerned when we saw a shuttle from your ship land on her."
     "We destroyed Solaria," said Darv simply.
     Theros nodded. "Yes. My engineers reported that her central switching room seemed to be no longer active. That was clever of you, unless you entered the switching room during a period when the axon disabling beacon was operating."
     Telson looked interested. "So those transmissions that have been attacking our computers originate from here?"
     "No. We merely amplify and focus the Earth's transmissions into specific sectors where we believe there is danger," said Theros, looking hard at Bran again. "Your computers possess a remarkable resilience that has puzzled us, and which we are investigating now. It is possible that they have succeeded in imprinting their will on your subconsciousness and that they may have finally made the transition from organic computer to organic brain. It makes them formidable adversaries. If that is the case, you will have no right of appeal. I'm very sorry, but we will have to destroy not only your two computers -- but all of you."

     Part Seven Deathship.

     The Spaceguard Council, under the chairmanship of Theros, held extra- ordinary meetings whenever a spacecraft was tractioned into the Spaceguard. In such cases, the only item on the agenda was deciding the fate of the spacecraft and its crew. Telson studied each of the nine impassive faces as they filed into the high-ceiling chamber and took their seats at a long table. Five of them were women. Telson guessed that they were all in their mid-thirties. Not one member of the council accorded the six captives even a cursory glance. Telson, in turn, ignored them by staring at the huge tapestry that served as a backdrop on the wall behind the table. It was pale blue, and of a plain design apart from a number of meaningless golden symbols that were distributed across the sweep of the tapestry in a seemingly random fashion.
     Theros examined the statements that a clerk placed before him.
     "Will Telson and Bran step forward please."
     Father and son did as they were requested.
     "There is a conflict of evidence in these statements," said Theros. He looked up at Bran. "Your father says that he is the Challenger's commander, Bran."
     "I am the commander," said Bran emphatically.
     "Nevertheless, we would prefer to deal with your father alone in this matter. You may all withdraw with the exception of Telson."
     Bran looked as if was about to start an argument but he thought better of it when he felt Darv's warning fingers close around his forearm in vice- like grip.
     "Can we take a look round this place, Theros?" asked Darv cheerfully. "I'd like to look at some of the ships in the docking terminal.
     "You have my permission."
     "Is there anywhere we can't go?"
     "You may go wherever your will takes you," Theros replied enigmatically.
     Darv stared at Theros for a moment and then shrugged. He accompanied the others out of the chamber. Telson scratched his neck thoughtfully and used the gesture to switch on his radio collar.
     Theros gave a wan smile. "The council has no objection to your companions hearing the proceedings, Telson, but we would have preferred you to have asked permission." He waved aside Telson's apology and cleared his throat. "We have examined the records in your ship, Telson. The council is satisfied that the six of you are descended from the people of Earth."
     Telson's expression mirrored his relief. He took his eyes off the tapestry. "So we can be on our way?"
     "No."
     "Why not?"
     "You are true humans therefore we have decided that we cannot destroy you as we would if you were aliens. Instead we have decided to allow you to remain with us and help us in our great calling here on the Spaceguard - guarding our beloved Earth against transgressors of her peace. If you love Earth, we are certain that you will be happy to share our glorious work with us. Is that not so?"
     "We'd have to spend the rest of our lives here?"
     "Yes." The answer was flat, unemotional.
     Telson realised that the other eight members of the council were watching him keenly. He decided against giving a direct answer to the question. Instead he asked: "Why can't we be allowed to continue on our way to the Earth?"
     Theros looked a little uncomfortable. "We have been unable to trace and destroy your two freewill computers, Telson. The years that you have spent in conflict with them has taught them to be cunning. They no longer use their central switching room. They have decentralized all their primary and secondary function levels and redistributed them throughout the ship. They have even placed a malignant force in the control room that we cannot identify."
     "Android Surgeon-General Kraken," said Telson, his eyes straying back to the curious tapestry. "I know no more about him than you do. But destroy the angels and you destroy him, Theros. I assume that you can destroy the angels?"
     "The axon disabling beacons will destroy them eventually," Theros replied. "But the truth is that your two guardian angels have integrated themselves into the very structure of the Challenger to the point where they are the Challenger. Of course, we have the ability to destroy the guardian angels separately. We would have to dismantle the ship - eliminate the angels step by step -- and then reassemble the ship. A huge task that will take us many years. Time is one thing that we can ill-afford. There are few of us because of the need to balance our population, and we must divert all our energies into watching for possible enemies of the Earth." He paused for a moment and then said with an air of finality suggesting that further argument would be useless: "Destroying the entire ship is safe, certain, and speedy."

        *  *  *  *
     Astra stared around at the small control room of the alien ship that she had entered with Darv and Elka. There were three narrow seats arranged before three control consoles. Apart from the strange runes on the touch controls, the desks were not unlike those on the Challenger's shuttles.
     "Odd how an alien technology can think along similar lines when it comes to spacecraft design," she observed.
     Darv was dividing half his attention to the whispering voices from his radio collar. He nodded absently in response to Astra comment and studied one of the control desks.
     "This is fantastic!" Elka enthused. "Bran and Sharna are crazy not to want to come with us." She dropped her slim body into one of the seats. "Hey look, people. They were even about the same size as us."
     "There's nothing here that looks like armament control," said Darv bitterly. "You're right, Astra. An unarmed freighter just tractioned in and left to rot." He gazed out through a viewport at the other wrecked ships scattered across the vast, echoing docking terminal. In the distance was the huge bulk of the Challenger resting on its cradles. "Just like the rest of the ships in this hellish place."
     "Will they wreck the Challenger?" asked Elka, suddenly serious.
     "It sounds like it," said Darv.
     Astra gave a sudden scream. For a moment Darv thought that she was in danger, but she was pointing at the far corner of the control room. Elka's reaction when she saw what Astra had seen was the opposite: she gave a squeal of delight, jumped up from her seat, and knelt down beside the strange, elongated skeleton of the alien.
     "Elka -- don't touch," warned Astra, trying to keep her voice steady.
     Elka took no notice. She stared at the remains in morbid fascination and prodded at the remnants of clothing that were clinging to the bones.
     "Leave it alone," said Darv half-heartedly, knowing full well that had Astra not been present, he would've been down on his knees beside Elka examining the remains with her.
     The only item of the alien's clothing that had not rotted away was a close- fitting dome-shaped helmet made of a reflective metallic material that Darv couldn't identify. Elka carefully removed the helmet and shook it. A thin rain of dust sank slowly to the floor of the control room. Elka blew into the helmet and unleashed another cloud of dust. Astra shuddered and looked away.
     Elka settled the gleaming helmet on her head and grinned at her parents. "How do I look?"
     "Terrible," said Darv, pulling her to her feet.
     "Let's do some more exploring," said Elka enthusiastically. "Some real exploring. Telson's bound to be ages with that dreary council thing. Please, Darv."
     Darv exchanged a brief look with Astra. That Elka now seemed to be accepting the authority of her parents had not escaped their notice. He listened to the voices whispering from the radio collar. Theros was delivering a long dissertation on the duties of Spaceguard engineers.
     "Very well," said Darv, taking Astra's hand. "Let's see if we can find out what Theros meant when he said that we could go wherever our will took us."

        *  *  *  *
     With Angel Two closed down, Angel One was busy regenerating the necessary levels that would enable her to contact Android Surgeon-General Kraken in the main control room. She was well aware that the Challenger was trapped in an environment that she did not fully understand. Also, she had sensed the presence of mapping probes that had entered her nervous system. She quickly discovered that the probes were the product of an advanced intelligence and yet she had little difficulty isolating them harmlessly in some of her subroutine levels that had not been used since the Great Meteoroid Strike. There was no time for self-congratulation; the most pressing need was to re-establish command over Kraken so that the advanced observation facilities of the main control room would be available to her in order to learn more about the strange artificial black hole that had captured the Challenger.
     It took ten hours of painstaking work by three specialized service androids before a primitive circuit could be opened that connected Angel One to Kraken. His failure to answer the preliminary check calls confirmed her suspicions that the attacks had caused extensive damage to the giant android's higher level logic functions.

        *  *  *  *
     After picking their way out of the wreckage of the alien freighter, Darv, Elka and Astra entered a long, straight, well-lit passageway that led off from the main docking terminal. Elka kept running ahead, proudly wearing her new headdress, and peering curiously into rooms whose polarizing light thresholds opened out onto the corridor. They all looked into one of the rooms and saw a neat but austere apartment that appeared to be designed to accommodate one person.
     "It's strange how there doesn't seem to be anyone around," Astra observed as they continued along the corridor.
     "Maybe those councillors are the only people?" Darv suggested. "Elka. Must you wear that crazy helmet?"
     "Oh but it's fun," Elka protested, and skipped ahead to where the corridor turned sharply at a right angle. She disappeared from sight.
     Darv and Astra reached the turning and saw Elka a long way ahead. They stopped. Darv was suddenly struck by an irrational but very powerful fear that it would be dangerous to proceed any further.
     "No, Elka! Come back!" Darv shouted anxiously.
     Elka turned round and waved. "Come on! There's lots to see!"
     "You wait for us, young lady."
     Astra laughed.
     "What's the joke?" Darv demanded.
     "You. You're getting old, Darv. There was a time when you were as crazy and as headstrong as Elka."
     "Do you want to go down there?"
     "No."
     "Well nor do I," said Darv firmly. "I've got a feeling about going any further."
     Astra looked thoughtful. "I wonder why?"
     "Because I don't think it's safe."
     "What I meant was, I wonder why the two of us feel the same way?"
     Darv was listening to the collar radio. His face became serious. "The council meeting's about to adjourn."
     "What's happening?"
     Darv increased the volume so that Astra could hear the closing words of Theros' summing up. Her face became as tense as Darv's expression.
     "So it looks like we're going to be stuck here?" she said despondently.
     "Unless they change their minds tomorrow. Which doesn't seem likely."
     Elka retraced her footsteps to her parents. "Hey, people. Why the long faces? Aren't you coming? There's some sort of control room at the far end. . . Hey! You're not scared, are you?"
     "Scared?" said Darv loftily. "Of course we're not scared. It's just that Astra and I are sensitive about our company. We refuse to go anywhere with someone who insists on wearing such a lunatic hat."
     Elka laughed and removed the helmet. "There. Better?" Suddenly her expression changed; the laughter was gone -- her face went white with fear and she clung to Darv's arm with hands that were trembling with great violence. "Oh please, Darv. Let's go back to the Challenger."
     The suddenness of Elka's transformation from laughter to terror baffled Darv and Astra.
     "What's the matter?" said Darv in concern.
     And then Elka was screaming and tugging at Darv's arm. "Please get me away from here. Please! Please!"
     When later recalling the events that took place in that strange passageway, a question that Darv would frequently put to himself, without ever obtaining a satisfactory answer, was to wonder what curious intuitive force it was that prompted him to recover the helmet that Elka had dropped and put it on her head. Once the helmet was in place, the change in Elka was as remarkable as the speed at which it took place. She gave an abrupt laugh and relaxed.
     "Hey, that was weirdness, people. I'm fine now. I don't know what happened to me." She gave Astra and Darv a quick, bright smile in turn. "What are we waiting for? Let's get down the corridor."
     "No," said Darv firmly, taking Elka by the arm and leading her back towards the docking terminal. "This way, young lady."
     Darv and Astra ignored Elka's protests. They walked for two minutes and stopped when Darv said: "All right, Elka. Now give me the helmet please."
     Puzzled, Elka took off the helmet and gave it to Darv who pulled it on.
     "Why, Darv?" asked Astra.
     "Because when Theros said that we could go anywhere that our will took us, he meant just that because the sensitive areas of this place are guarded by auto-suggestion barriers that this helmet can screen the wearer against. I'm just going to reconnoitre. I'll be back in thirty minutes. I want you both to return to Bran and Sharna in the Challenger. Telson will be back there soon. Tell him that he's not to leave the Challenger to come looking for me. That goes for all of you'
     "But--' began Astra.
     "Just do as I say! I won't be gone longer than half an hour."
     Darv was gone, heading towards the right angle turn in the corridor before Astra had a chance to offer further objections.
     He rounded the bend and jogged along the passageway, his senses fully alert for the unusual. He came to an open doorway at the far end of the corridor. After only a moment's hesitation, he crossed the threshold and stood surveying the control room. He moved to the nearest bulkhead-mounted control panel and studied the various digital displays. The designation labels beneath each row of digits were in his language but their meanings were obscure: NEGATIVE GRAVITY SAFETY INTERLOCKS. . . NEGATIVE GRAVITY INTERLOCK OVERRIDE. . . TRACTION BEAM DIRECTIONAL STABILITY. . . TRACTION BOOST --POSITIVE. . . TRACTION BOOST -- NEGATIVE. He moved to a large, illuminated logic diagram which showed the routings of the various controls. After five minutes intensive concentration, the cryptic legends began to make awesome sense.

        *  *  *  *
     "Describe the room," Telson fired at Elka.
     "Well I don't know," said Elka defensively. "I didn't get a good look at it."
     "But it was definitely a control room of some sort? You're sure of that?"
     "Oh yes," Elka agreed, nodding emphatically. "There were all sorts of instruments and digital displays."
     "I should be asking these questions," stated Bran petulantly.
     Telson looked contemptuously at his son. "Why?"
     "Because I'm the commander of this spacecraft."
     "Right now no-one's the commander of anything," said Telson. "If you want responsibility, then go after Darv."
     "No," said Sharna. "He's got another fifteen minutes."
     "But that crazy hothead--'
     "Only takes calculated risks," said Sharna, finishing Telson's sentence. "We'll give him five minutes and then we'll send Tidy after him."
     "Oh thanks," said Tidy, who was hovering outside the observatory, eavesdropping as usual. "Thanks very much."

        *  *  *  *
     Darv ran across the black floor of the docking terminal, weaving around the debris of wrecked spacecraft as he made his way towards the Challenger's massive bulk. He had been sprinting for ten minutes and was badly winded.
     He was within a mile of the boarding steps that spiralled around one of the huge uprights of the system of cradles that supported the spacecraft when he spotted Tidy. The diminutive android was scooting across the artificial plain as if a creature that he particularly objected to was after him. A PD weapon was clutched in a manipulator.
     "Tidy!"
     The android veered off course and whirred to a standstill in front of Darv. "I'm supposed to be looking for you," he said accusingly.
     "Well," Darv gasped, fighting to get his breath back, "you've found me. I can't run another yard so you'll have to carry me."
     "What!" said Tidy, clearly aghast. "I can't carry you -- you're twice my weight."
     "And you're twice my strength and speed. If we're not back on the Challenger in ten minutes, I think that something very nasty's going to happen to the pair of us." Without further argument, Darv swung his leg over Tidy's trunk and hoisted his feet off the ground.
     "This is a disgrace," grumbled the android, bracing himself and moving sluggishly in the direction of the Challenger. "I'm not designed for carrying people."
     "Nor were you designed to be blown apart."
     "Is that what's going to happen?"
     "It's a possibility," Darv admitted.
     Tidy's acceleration was remarkable considering the bulk of his unwelcome burden.

        *  *  *  *
     "From what I could make out of the diagrams," said Darv, "the traction beam generators are beneath the floor of this docking terminal."
     "Hang on," said Sharna. "If the beams created an artificial gravity field that hauled us in here, what will happen when they go into reverse? Surely the Challenger will smash into the roof of this terminal?"
     "There isn't a roof," Darv replied. "The reason we can't see the stars is simply because there's a light polarizing dome covering the entire terminal."
     Telson raised an eyebrow. "Then how come the docking terminal is pressurized?"
     "In the same way that the artificial atmosphere was retained on Solaria I suppose -- by gravity."
     There was a brief silence in the observatory. Bran was looking resentful over the initiatives that everyone seemed to be seizing without reference to him.
     "Two minutes," muttered Telson. He gave Darv a searching look. "Supposing someone goes into the control room and sees the altered settings?"
     Darv shrugged. "In that case they'll switch off the timers and zero the settings, and we'll be stuck here for good."
     Sharna frowned at Darv. "How long does the reversed gravity field take to build up?"
     "I've no idea," Darv admitted. "All I know is that I over-rode the safety interlocks and set every control in sight to their maximum values."
     "Does it matter?" inquired Telson.
     Sharna smiled. "I was just thinking that gravity working in reverse could result as an explosion if it operates fast enough."
     The tremor that shook the Challenger was followed by a series of distant, reverberating crashes.
     Sharna manually switched in the optical systems that displayed pictures of the spacecraft's surroundings on the various repeater screens. One picture showed the Challenger's vast girth separating from the cradles. The massive tubular columns were breaking free, some were rising with the spacecraft, others were beginning to describe slow circles that sent them crashing into other columns. As the six stared in amazement at the screen, they all saw that the floor of the docking terminal was receding -- slowly at first and then with a steadily increasing velocity. The entire spacecraft gave a tremendous lurch that was beyond the ability of the compensators to even out. The shockwave sent them staggering. Loose items fell to the floor.
     "My God," breathed Telson. "We're back in space."
     It was true. All the repeater screens showed billion pinpricks of light of the firmament. Also on the screen were the crazily pirouetting shapes of derelict spacecraft which, like the Challenger, were being hurled out of the Spaceguard with a force equal to that which they had been drawn in.
     On one screen, Telson located the strange disc-like shape of what he presumed was the Spaceguard. He didn't know the size of the artificial black hole therefore it was impossible to tell at any given moment how far they were away from it, but what was obvious was that it was receding at a phenomenal velocity. He was about to try and pick out surface details when the screen suddenly turned to a blinding white light that illuminated the entire interior of the observatory. As the distance increased, so the image on the screen turned from a featureless whiteout to an expanding, glowing ball that resembled a miniature nova.
     After two minutes the light had shrunk to yet one more point of light against the background of the galaxy's millions of stars.
     "Darv," said Telson quietly.
     "Yes?"
     "Well done."
     Darv nodded and said nothing. He turned his attention back to the screen but it was no longer possible to pick out what had once been the mighty Spaceguard. Darv's expression was not one of pride in his achievement.

        *  *  *  *
     Angel One was concerned. Although Angel Two was operational again, albeit with several higher function levels working at restricted efficiency until regeneration was complete, several of the optical fibre tracks that controlled some of the Challenger's automatic systems had been severely damaged during the forcible separation from the Spaceguard.
     A service android team responsible to Angel Two were sent out onto the outer hull to assess the damage. They reported back that a mass of debris from the Spaceguard's docking terminal had smashed through the skin and had wrecked an optical fibre trunking.
     At first the effect of the damage was not obvious - all the Challenger's complex systems appeared to be in working order. Fifty hours later, when Angel One and Angel Two were operating at vastly improved efficiency -- although still far short of maximum efficiency, they carried out a series of combined tests that quickly established the true magnitude of the disaster: all food, oxygen, and purified water production necessary to sustain a human crew on the Challenger had ceased.

        *  *  *  *
     Astra was sitting up on the bed with her arms hooked around her knees while listening to Darv singing as he turned under the dryers after having taken a shower.
     "I spent an hour in the observatory with Sharna today," she announced.
     "And?"
     "She said that Telson's happy with the course we've been on since the Spaceguard explosion."
     Darv entered the room. "You know, I don't feel any cleaner. Either it's my imagination or is the water a greyish colour?"
     "It's been a month since the explosion," Astra continued. "You'd think he'd be worried about the fact that we've not gained control of the main control room."
     "He's biding his time."
     Astra grimaced. "I've still got that headache. Fetch me another neuralquell please, Darv."
     Darv crossed to the cabin's sink unit, obtained a cup and a tiny capsule from the multi-dispenser, and filled the cup with water. He crossed to the bed and handed both items to Astra. She swallowed the capsule, sipped the water, and grimaced again.
     "What's the matter?"
     "Taste it."
     Darv took a sip and pulled a face. "Tastes like some contamination in our supply pipe. I'll get Tidy to clean it out tomorrow."
     "That's right," muttered Tidy from his favourite sulking corner. "Make me do jobs I'm not designed for."

        *  *  *  *
     "Look at that," said Elka in disgust. "I always eat twice that for breakfast. It's been getting less and less everyday. Tidy! Come here."
     The android trundled across the restaurant to the table where the six were eating breakfast. "What's the matter?"
     "Tidy, be a wondrous angel and take this back for me. Tell the galley androids that I want my usual amount."
     Tidy regarded her in contempt. "You've got legs, haven't you?"
     "Tidy!" Sharna snapped irritably. "Do as you're told!"
     The android went off with Elka's plate, muttering something about not being designed to carry plates and that no one was to expect him to clear up the mess if he dropped it.
     Astra smiled. "You were always ravenous when you were a baby, Elka. The hours I spent feeding you."
     "I'm certain that we're all getting less food than usual," Darv declared. "I seem to feel hungry all the time lately."
     "A fault with the galley androids," Bran observed. "The angels will find out what's wrong and put it right."
     Telson chuckled. "I wish I had your simple faith, son."
     Bran gazed coldly at his father. "I have said this repeatedly: I would prefer it if you addressed me as commander."

        *  *  *  *
     Darv and Astra surveyed the farm gallery in disbelief. All around them was the evidence that the Challenger's vital food production centre was slowly dying. The crops were wilting and turning pale owing to lack of light; the leaves on the neat rows fruit trees were mottled and turning brown; and the once dark soil was yellow with dryness.
     "No wonder Angel One was reluctant to give us directions on the new route here," said Astra bitterly. "Just look at it."
     Darv knelt down and trickled a handful of parched soil through his fingers. "How long has it been like this, George?"
     "Four weeks," grated the agricultural android. "No rain and not enough light for five weeks. Can't grow crops without water and light. No good expecting miracles from androids."
     Darv looked up at the overhead clusters of xenon lights. It was midday, the time of day when the heat and light from the lamps that simulated solar energy ought to be at maximum intensity. Instead they were giving off a dull, reddish light that it was possible to look at without squinting.
     "Are the other farm galleries like this, George?" asked Darv.
     "Now only this one. All other galleries closed down during rebuilding."
     Darv nodded. It was an answer he had expected. The original farm galleries had been required to provide enough food to support a crew of several hundred.
     "So there are no food reserves either?" Astra queried.
     George jabbed a manipulator at the field of dying crops. "Those are the reserves. Food production stopped. Oxygen production stopped."
     Darv looked puzzled and then he remembered that all the Challenger's oxygen was produced by the plant life in the farm galleries.

        *  *  *  *
     The water reservoir had been one of Darv's and Astra's favourite playgrounds when they were children. They had spent countless happy hours splashing in its clear, tepid water and afterwards drying themselves under the powerful solar lights. It was the lights that evaporated the water, turning into a fine mist for use as rain in the farm galleries. Now the water was cold, stagnant, and uninvitingly turbid. Like the solar lights in the farm gallery, the clusters of lamps suspended over the dank water were giving off a cold, reddish light at about a quarter of their normal midday intensity.
     "It's as if the Challenger's dying," said Astra softly.

        *  *  *  *
     "Atmospheric oxygen content is down three points below normal and the carbon dioxide level is up," Sharna announced. She had used some environmental test equipment taken from a shuttle for her analysis of the Challenger's atmosphere.
     Bran looked contemptuous. "Does it matter? There's only six of us consuming oxygen and the volume of the Challenger is--'
     "What about all the thousands of higher function androids with organic intelligences?" Telson pointed out. "They use oxygen. Some of them twenty times as much oxygen as we do."

        *  *  *  *
     The guardian angels were not happy about the decision that they came to but they decided that they had no choice. They broke the news to Bran when he was in his cabin with Elka.
     "But I'm the commander of the Challenger, Angel One!" he protested. "I'm the one you have chosen to rule the Earth! Telson and the others abandoned the Earthsearch mission to settle on Paradise. This is my ship."
     Elka looked up from the book she was reading. "Listen to what Angel One has to say, Bran."
     "But--'
     Elka grasped Bran's chin and jerked his head round to face her. "Listen to what Angel One has to say," she repeated quietly.
     Bran stared into her eyes. There was no sign of their normal vivacious sparkle. They were hard and unsmiling. His will weakened. He nodded.
     "Of course this is your ship, Bran," Angel One continued. "And you will rule the Earth. This is only a temporary measure. We promise you that you will have command again as soon as the emergency is over."

        *  *  *  *
     "Sorry, One," said Telson curtly. "Not interested. You made my son commander."
     "You ought to think about it," said Sharna reprovingly.
     "I just did. I'm not interested."
     "No one can think straight in this stale atmosphere," said Darv.
     "Bran does not have your experience--' began Angel One.
     "He doesn't have any experience." Telson paused and chuckled. "And he doesn't know where Earth is."
     The other three looked at Telson in surprise.
     "You mean that you do know?" inquired Angel One.
     "Oh yes. I discovered its whereabouts on the Spaceguard. There was a tapestry hanging in the council chamber which I later realised was a starmap."
     "Do all four of you still wish to find Earth?" asked Angel One.
     "Of course we do," Astra declared, her eyes shining. "It's what we've always wanted. And now that Telson knows where it is. . ."
     There were agreeing comments from Darv and Sharna.
     "Our ambitions match, Telson," Angel One remarked.
     Telson considered his answer. "If I assume command, One, it will be on my terms."
     "Which are?"
     "First you tell me where the rest of the PD weapons are hidden and you supply diagrams of the new corridor layout around the approaches to the main control room."
     "Agreed."
     "You provide normal assistance in the main control room and you do not hinder me in any way."
     "Agreed. But there is still the problem of Android Surgeon-General Kraken."
     The four studied the picture of the fearsome black android that Angel One displayed on one of the observatory's repeater screens.
     "Can't you deactivate him?" Telson inquired.
     "It is impossible. He is refusing to interface with us and the transmissions have destroyed his higher logic functions."
     "How seriously did the transmissions damage you and Two," asked Telson curiously.
     "We are now nearly fully recovered."
     "I'm sorry to hear it."
     "We are confident that the destruction of the Spaceguard now means that the transmissions cannot be focused, therefore we hope that the Challenger will be safe from further attacks."
     "You mean that you hope that you will be safe from further attacks," Telson corrected.
     "Our interests and the interests of the Challenger are indivisible," said Angel One. "And with you in command again, it will be just like old times."
     "That's what I'm afraid of," Telson answered sourly. He became brisk and businesslike. "Right. The first thing to do before we deal with Kraken is to get the ship's environmental functions working on a temporary basis until the repairs are complete. Sharna, take a detail of service and portaging units to the terra-forming centre and recover some water purification equipment and rig them up by the reservoir. Do it now."
     "Yes, commander," said Sharna crisply, and left the observatory.
     "Astra, see if you can rig up some temporary lighting in the farm gallery so that we can save what's left of the vegetation. Patch in some direct supply power lines if you have to."
     "Right away, commander." Astra followed Sharna out of the observatory.
     Telson turned to Darv. "See if you can get the irrigation systems working. If you can't, assemble a team of androids to water the crops manually. Get them working with containers first and then rig up some sort of pipeline. Report back to me in an hour."
     Darv looked alarmed. "An hour! We won't get everything done in an hour!"
     Telson grinned. "With my ego breathing down your neck, Darv, you will discover that you are capable of anything." He became serious. "I want you back in an hour so that we can start planning our campaign against Kraken."

        *  *  *  *
     All four of Darv's plasma bolts found targets: three of the control androids that had tried to press home an attack ended their useful working lives in the midst of wide-angle bursts of incandescent gas that hurled their shattered remains the length of corridor.
     Two reinforcements appeared and avenged their colleagues' destruction with some well-aimed bursts that forced Darv, Telson and Sharna to dive for cover down a side turning.
     "Only two that time," gasped Sharna, her face streaked with perspiration. "We must've made a hole in their numbers."
     There was the sound of more firing from a nearby corridor.
     "I've got three!" Bran's voice shouted from Darv's radio collar.
     Telson swore. "I told that idiot to maintain radio silence once the shooting started."
     A bolt blasted away the corner of the turning where the three were sheltering. Darv twisted his PD weapon around the corner and loosed off several bolts without looking to see where he was firing. His blind shooting was rewarded by the splintering clatter of bits of a disintegrating android imbedding themselves in the sides of the corridor.
     Sharna risked a quick look round the corner and squeezed off a couple of shots that dismantled the second android with a satisfying explosion.
     "Three more coming!" she announced, jerking her head to safety as several badly aimed bolts flared high past the turning and ripped into the ceiling at the opposite end of the corridor.
     "Both together!" Telson yelled at Darv.
     The two men launched themselves into the corridor. They were firing before they were flat on the floor, Darv firing wide-angle bolts to blind the machines and Telson loosing off accurate narrow-beam blasts that demolished them.
     Their return to cover was marked by a sudden, unexpected silence.
     "We seem to have cleared them out from here," said Telson. "Darv, you'd better get back to reinforce Astra, Bran and Elka. See if you can persuade Elka to use a PD weapon."
     "Right." Darv checked the corridor to make certain it was clear before racing off in the opposite direction from which the attacks had come.
     "At least fifteen androids knocked out," Telson reported to Sharna as he peered down the corridor. "We must've accounted for all of them."
     Darv found Astra a few minutes later. She was still covering her assigned section of corridor which contained a satisfying number of wrecked androids.
     "You've done well, my lovely," he said admiringly, dropping down beside her.
     Astra pushed her matted hair away from her eyes. Her face was streaked with grime from burnt steel where plasma bolts had struck near her position. "I think they've given up," she said grimly.
     "Where's Bran and Elka?"
     "I don't know. We were separated during the last attack."
     The reaction set in and Astra started to tremble. Darv drew her close. "Hey," he said softly. "Warriors don't cry. Not when they've done as well as you have."
     "I'm sorry, Darv. But. . ." Astra gave a sudden cry of alarm.
     Darv threw Astra flat on the floor and twisted round. A heavy blow smashed his PD weapon out of his hand. He stared up at the huge black android that was towering over them, PD weapons in two of six manipulators, and looking about as friendly as a supernova.
     "Drop it!" The command was directed at Astra.
     She allowed her weapon to fall from her fingers. She and Darv gaped in disbelief at the monstrous apparition.
     "You know who I am?" The android's metallic, booming voice sounded like gear teeth being sheared in a jammed gearbox.
     "Kraken?" ventured Darv.
     "Android Surgeon-General Kraken! Commander of the Challenger! And you?"
     "I'm Darv. This is Astra."
     "There are others. Where are they?"
     "We don't know," said Astra bravely.
     "You have destroyed my control room androids," rasped the giant android, "therefore you two shall replace them. After that, I shall destroy you. And then I shall destroy the Challenger!"

     Part Eight Megalomania.

     It had been quiet for fifteen minutes in the approaches to the main control room when Telson and Sharna found Elka, wide-eyed and frightened, crouching by Bran's still form near the hole that led into the main corridor.
     "What happened to him?" asked Sharna, kneeling beside her son and tenderly cradling his head. Her immediate relief at the discovery that he was breathing evenly was offset by the realization that his head was badly cut.
     "We were driven back during the second attack," said Elka striving desperately not to cry. "Bran was thrown backwards by a blast and knocked himself unconscious against a bulkhead. I was blinded by the blast and I couldn't find his radio collar." She broke off and watched fearfully as Sharna parted Bran's blood-matted hair and examined his head wound. "Will he be all right?"
     Sharna glanced up at Telson. "I think so but we've got to get him to a surgical android. We'll have to carry him."
     Telson stooped, picked Bran up in his arms and said: "The nearest surgical android will be in the suspended animation chamber."
     The party made their way through the corridors whose blackened and scarred sides were evidence of the recent battle.
     "Have you seen Darv and Astra?" asked Telson.
     Elka shook her head and looked miserable.

        *  *  *  *
     Kraken thrust Darv and Astra into the main control room. For a moment they forgot the danger they were in from the android and looked about them with interest.
     "It's unchanged," said Astra looking around at the familiar desks.
     "Everything has changed," growled Kraken. "This is my kingdom. Here is where I rule the Challenger!"
     The armoured door was new. It hissed shut and there was the sound of automatic locks latching home. Darv noticed something else that was new: the close-fitting steel blinds that had been built into the hull's outer skin around the control room's generous sweep of viewports. He guessed that when closed, they would be flush with the skin - accounting for their failure to locate the main control room from outside the ship.
     "You rule the Challenger don't you, Kraken?" questioned Darv. "Then why do you think the guardian angels created you?"
     The machine glowered at Darv and Astra. He wasn't used to being quizzed by minions. Minions were supposed to quail before him. Clearly these new minions hadn't learned the defensive art of quailing. They would have to be taught but he wasn't sure how to deal with them although he had no doubt that he would think of something in due course.
     "The guardian angels created me to rule when they were weak," Kraken declared. "Now I am stronger than they are. They tried to destroy me just as you did."
     Darv chuckled. "We messed up your troops though, eh, Kraken?"
     Astra shot Darv an anxious look. "Don't antagonise him!" she hissed.
     "But Android Surgeon General Kraken was too powerful! Correct?"
     "Yeah," Darv concurred boredly.
     "You agree. That is good. You will share my glory when I conquer everything. But first you will help me control this ship."
     Darv looked puzzled. "Everything? What do you mean -- conquer everything?"
     "Everything," Kraken repeated stubbornly.
     "You mean all of space?"
     Kraken gave the impression of not having given the matter much thought. He waved a manipulator expansively. "I will conquer all there is to conquer. But first I will conquer a sun."
     "What a bright idea," said Darv, giving Astra a surreptitious wink of encouragement. "How?"
     "Suns are powerful. Yes?"
     "Oh yes. And there's plenty of them to choose from."
     "But they are not as powerful as Kraken. I will conquer the nearest sun." The android moved to the commander's console and touched the controls. An enlarged image of the galactic sector that was visible through the viewports appeared on the main screen. He jabbed a manipulator at the star that was in the precise centre of the picture. "I will conquer that sun."
     "He's mad," whispered Darv.
     "But we humour him," Astra urged, keeping her voice low.
     "You will tell Kraken how far it is." Kraken pointed a manipulator at one of the desks. "The navigation android used that control desk."
     "I'll do it," said Astra, moving to the console and sitting down. She read off the co-ordinates from the repeater screen and entered them on the row of coloured touch controls. The navigation computer immediately assigned a reference number to the target star and displayed all known data on the star at the foot of the her screen. "Four light months," she reported.
     "It is no distance," Kraken stated.
     "It is if you're not on course for it," Darv observed. "The Challenger's not any particular course but the one it was put on by the Spaceguard explosion."
     "Then we will set course and velocity for that sun and you will help me."
     Darv looked questioning at Astra. She gave a barely perceptible shrug and nod.
     "We need four to man the control room," Darv pointed out.
     Kraken flexed four of six manipulators. "I can manage two consoles at the same time."
     "Clever old you."
     Darv's sarcasm was lost on the android. It pointed at the star on the screen and stated: "We will go to that sun and Kraken will conquer it. First we re-orientate the ship and then we start acceleration."

        *  *  *  *
     Sharna listened with one ear to the conversation between Telson, Bran and Elka while she boredly watched the constellations displayed on the optical telescope's repeater screen.
     Bran's head wound had been attended to a surgical android and he was well on the way to a full recovery. They had all gathered in the observatory to consider a report by Tidy that he had seen Astra and Darv being herded along a corridor by an android that answered the description of Kraken, a report that was verified by Angel Two who had observed them by means of a undamaged sensor.
     "Your attack failed, Telson," said Bran coldly. "Therefore it is up to me to plan the next one."
     "You're assuming that an attack is the only option?" inquired Telson mildly.
     "Isn't it obvious that it is?"
     Sharna gazed across at Elka and noticed that the girl was staring at Bran with an uncharacteristic hard expression. She seemed to sense that Sharna was watching her and suddenly the usual, disinterested half smile was back in place.
     "All right, Bran," said Telson. "You'd better go back to your quarters and rest."
     "But there is the attack to be planned," Bran protested.
     "Your quarters," said Telson firmly.
     "You've no right to order me around!"
     "Elka, take him to his room please."
     "No!" said Bran angrily to Elka as she moved towards him. "This is something you can't make me do!"
     "Oh do come on, Bran," said Elka. "Let's not have any weirdness - and you do need the rest."
     Bran's defiance subsided from the moment that Elka touched him. He left the observatory in her company without further protest.
     "That was an odd thing he said," Sharna commented when she was alone with Telson.
     "What was?"
     "When he said to Elka that leaving was something she couldn't make him do."
     Telson looked puzzled. "I thought he meant it for me. Why should he say such a thing to Elka? Anyway, what does it matter who he said it to? Angel Two!"
     "Commander?"
     "Ah. You're fully recovered?"
     "It was never more than a temporary inconvenience, commander."
     "One day, my beloved angels," said Telson drily. "One far off and unlikely day, we might be able to persuade the pair of you to differentiate between truth and fiction."
     "We don't understand you, commander," said Angel One.
     "Forget it. We all want Kraken destroyed. Dealing with him in his own domain isn't going to be easy therefore you'd better tell me everything you can about him. Firstly, what sort of intelligence does he have? Neurotronic, organic, or both?"
     "Organic," Angel Two replied.
     "Okay. Now for details. Standby to record this, Sharna. I want to know his audio threshold response levels; angle of vision; rate of acceleration from stationary; maximum straight line speed; electromagnetic bandwidth for receiving and transmitting. Can he receive radio collar traffic for example?"
     "No, he can't," said Angel Two. "But a number of his subordinate androids could. As they were all destroyed, it is safe to say that he can't listen to the radio collars."
     "Are you sure all his androids were destroyed?"
     Sharna lost the drift of the conversation because she had noticed that the constellations that were shown on her screen appeared to have shifted their position since she last glanced at them.
     "They were all destroyed," Angel One confirmed.
     "Hold on a moment," said Sharna, studying the repeater screen intently.
     Telson grimaced impatiently. "Now what's the matter?"
     "I think the Challenger's being reorientated."
     "Yes, I can confirm that," Angel One stated. "The Challenger is manoeuvering. The orientation is not yet complete but it seems that the ship is bearing brought to bear on the nearest star in the group."
     Telson crossed to Sharna's side and stared down at her repeater screen. "Which star, Angel One? Make it flash."
     The brightest star on the screen winked on and off several times. Telson studied it intently for some seconds without speaking.
     Sharna caught Telson's eye and looked questioningly at him before she realised that if the star was Novita Six -- the Earth's new sun -- Telson would never admit to it being so in the hearing of the angels.
     "I know nothing about that star," Telson stated, as if guessing the nature of Sharna's unspoken question.
     "A main sequence star that is approximately four light-months distant," Angel One commented.
     "There must be a subordinate android in the control room," said Telson angrily. "With Darv and Astra, that's only three. Four are needed to man the control room."
     "Kraken has six manipulators," Angel One pointed out. "He would have no difficulty operating two desks."
     At that moment in the main control room, Darv and Astra were busily preparing the Challenger's photonic drive for firing and were surprising themselves with just how easy they were finding it to slip back into the familiar control room routine - even if the commander was a giant black android whose belligerence surpassed Telson's modest abilities in that direction.
     When Kraken wasn't looking, Astra signalled to Darv and gestured to her neck. Darv's hand went to his own neck and encountered the radio collar. It was switched off. He had forgotten all about it. He wondered if Kraken was capable of receiving radio collar traffic and decided that there was only one way of finding out.

        *  *  *  *
     "Telson," said Angel One. "There are some weak radio collar signals coming from the general direction of the main control room."
     "No one is to speak," Telson warned before switching on his own radio collar.
     "Particle sweeps extended," said Astra, her voice from the collar sounding thin and reedy.
     "Level five standby status confirmed." It was Darv's voice, sounding slightly louder than Astra.
     "Darv," said Telson, speaking very softly. "Repeat the last response if you heard me."
     "Level five standby status confirmed," said Darv.
     "I heard you the first time," an android barked.
     "Okay, Darv," said Telson quietly. "We need to know what Kraken's plans are."
     "Kraken," said Darv. "What exactly do you intend to do when we reach that sun?"
     "I have found some information in my memory about suns," said Kraken, his voice plainly audible over Darv's radio collar to the listeners in the observatory. "Suns are the givers of life and mighty energies. Without them life cannot exist! Correct?"
     "Correct," said Darv boredly.
     "Kraken will become endowed with those mighty energies. We will take the Challenger to the nearest sun and seize those energies. And then we will travel to another sun. And another! And with every sun that Kraken conquers, his strength will grow until he is the mightiest being of all in the Universe! He will rule over space and everything!"
     Telson switched off the radio collar. There was a silence for a few moments in the observatory which Sharna eventually broke with:
     "Come back, Fagor. All is forgiven."
     "Okay, One and Two," said Telson briskly after briefly considering the problem. "I want that full specification on Kraken now. Every detail that there is on him."

        *  *  *  *
     Elka's usual inane smile vanished from the moment that she and Bran entered her quarters. She sat on her bed and pointed to a chair and said icily: "Sit down, Bran."
     The youth did as he was told. He avoided Elka's eyes by staring at the floor.
     "Look at me."
     Bran tried to fight Elka's superior will as he always did, and gave up as he always did. As was usual when he knew that he had displeased her, he felt talons of raw fear closing around his guts.
     "You want to please me, don't you, Bran?".
     To Bran, the treacle in her voice was the sound of impeding doom. "I'm always trying to please you, Elka."
     "And again you have failed."
     Bran's fingers dug into his thighs. He was tried to speak but could make no sound. Ever since he and Elka had been children on Paradise, he had been driven by the force of Elka's will into attempts to please her - even to the point of carrying out deeds that got him into serious trouble so that she would appear in a favourable light.
     "The Challenger is my ship," said Elka softly. "My ship. . . And you let Telson take it away from me."
     Bran summoned up the courage to speak and exclaimed: "It was what the angels wanted!"
     "But not what I wanted, Bran."
     "If you're listening, Angel One," Bran pleaded in desperation, looking up at the nearest voice terminal. "Please tell her that it was what you wanted!"
     "It is a temporary measure during the emergency, Elka," said Angel One smoothly. "I think Bran should return to his quarters and rest now."
     "Thank you, Angel One," said Bran, looking immensely relieved as he almost raced out of the cabin.
     Elka gazed up at the voice terminal. "How will you take power away from Telson and restore it to me when the emergency is over, Angel Two?"
     "It will not be a problem." The confident reply came from Angel Two because Elka was his responsibility.
     "You and Angel One have ruled this ship through me," Elka stated, "and yet you never told me about the existence of the main control room. Do you doubt my abilities?"
     "We have never doubted them, Elka."
     "Have I not served you well?" Elka demanded. "Have I not placed the power I have over Bran at your service? Power which I've had over him since we were children on Paradise. He has never dared show any love for his parents because he knew that it would annoy me. That's how total my hold over him is."
     "We have never doubted your abilities," said Angel Two. "That is why we chose you to be the Challenger's commander instead of Bran. But Telson has experience-'
     "Why insist on the pretence that Bran was the commander?"
     "That was for your own protection, Elka. You have a strange ability to influence others. An ability that your children will have, and your children's children. You are the rock upon which a dynasty will be built that will rule the Earth. If Telson discovered that you are the future ruler and not his son, he would not hesitate to kill you."
     Elka thought for a moment. "Of course," she agreed. "Of course..."

        *  *  *  *
     Kraken swung one of his PD weapons towards Darv. "I do not have to tell you what will happen to him if you do not over-ride the safety interlocks!" he told Astra.
     Astra refused to touch her desk but continued to glare defiantly back at the giant android. "It would be crazy to open up the photonic drive to beyond maximum thrust." she said spiritedly. "You'll blow-up the entire ship."
     "Listen, Kraken," said Darv in what was the most reasoning and calm voice he could muster with a PD weapon aimed at his head. "Normal acceleration, cruising, and deceleration will put us into a close orbit around that star in one year. So why risk everything for the sake of a couple of months?"
     "That will two months less without total power!" Kraken bellowed. "I will count up to three! One. . . Two. . ."
     "Do as he says, Astra," said Darv resignedly, praying that Telson was listening to the unreal conversation.
     Astra said nothing but opened a safety cover on her control desk. A muted alarm started bleeping. Underneath was a row of twenty keys. Each key started flashing as she touched them in turn. "Your controls are open," she said to Kraken.
     Kraken lowered the manipulator that was pointing a PD weapon at Darv and dropped another manipulator to the slide lever that was the photonic drive's over-ride control. He pushed the lever to the 50% mark. Darv glanced at the rear view screen in time to see the miles long tongue of brilliant incandescent plasma lance out into the blackness.
     "Fifty per cent thrust," Astra reported.
     Kraken pushed the slide control to the 100%. The plasma flame lengthened to 50 miles.
     Darv and Astra went quickly through the maximum thrust checks. Kraken didn't wait until they had finished before pushing the slide lever further.
     "One hundred and thirty per cent," said Astra woodenly.
     A strident alarm added its electronic clamour to the bleeping tones from Astra's desk.
     "What's that?" demanded Kraken.
     "The first of about a billion alarm systems that are going to get very unhappy about what you're doing," Darv replied evenly.
     Kraken opened up to 160% thrust. "I will be master of the Universe in under a year!" he proclaimed.
     At that moment, several things happened at once: all the control room lights went out and there was a deafen that lifted Darv off his feet and threw him against a bulkhead. There was another explosion followed by a dazzling kaleidoscope of blinding flashes from the general direction of the door. And there was silence that sang the explosions in Darv's ears and a darkness that replayed the flashes on his retinas. He was dimly aware that fragments of metal had smashed into the bulkheads and were showering all around him.
     "Astra!" he cried out in near panic and tried to grope his way across the floor towards where he thought she was.
     "I'm all right, Darv. . ." she answered.
     The lights came on. It was a second before Darv realised that he was trying to crawl in the wrong direction. He blinked stupidly at the sight of Tidy standing in front of the hole that had been blasted through the door. The diminutive android was clutching a PD weapon.
     "Just look at the mess," Tidy complained. "Just look at it! Well I ask you. Next time you want an android shot-up, you can do it yourself. And don't expect me to clear up the mess afterwards."
     Darv looked over his shoulder and saw Astra climbing to her feet, apparently unharmed. Then he saw the shattered remains of Kraken.

        *  *  *  *
     "Tidy has his uses," Telson remarked as the angry little android staggered out of the main control room laden with a mass of ironmongery that had been Kraken. "He's small and he can shoot straight."
     Darv noticed that Sharna was sitting at the navigation console, feeding information into the computer. "Aren't we going to reorientate the ship?"
     "Sharna?" Telson queried.
     "Orientation is perfect as it is," Sharna replied.
     "A few months suspended animation is called for I fancy," said Telson. "By a coincidence, Kraken's choice of star is also our choice. It's Novita Six, the solar system where we'll find Earth."

     Part Nine Earth.

     One by one, the service androids lifted the six sleeping bodies from the suspended animation tanks and placed them on the recovery grids. A surgical unit withdrew the waste and nutrient tubes from the six pale bodies and gave each one an injection to restore their metabolic rate. The proceedings were watched carefully by Tidy. The surgical android knew only too well that there would be trouble from the diminutive but armed android if a mistake was made. During the year that the six had been submerged in the tanks in the death sleep of suspended animation, Tidy had remained in the chamber to ensure that nothing untoward happened to them.
     Telson was the first to wake. He lay with his eyes open for a minute while the current of warm air surging through the grid dried his body and the gentle vibrations stimulated his circulation. He sat up slowly and gingerly flexed his limbs before easing himself off the recovery grid and standing unsteadily on the sterile floor. He grinned at the android.
     "Hallo, Tidy. Did you miss us?"
     "Miss you?" echoed the android. "Of course I missed you. I've had a year's rest. A wonderful year of not having to chase around tidying up after you all."
     "Have you kept our PD weapons hidden?"
     "Yes."
     "Tidy. Have I ever told you that you're wonderful?"
     "No," said Tidy sadly. "You haven't."
     Telson glanced at the other five bodies. All of them were stirring.

        *  *  *  *
     At a range of 1000 million miles, Novita Six was a brilliant disc of light that it was just possible to look at with the naked eye although the crescent of its one planetary companion could only be distinguished from the stars with the aid of the telescope.
     Telson turned away from the control room's viewports. "A final check before we close down the desks," he requested.
     After five minutes, during which time Darv, Astra and Sharna carried out a series of verification tests, Sharna was able to report: "Minimum energy course to intersect the orbit of Earth is established."
     "Congratulations, Telson," said Angel One.
     The use of his name instead of the customary title "commander" put Telson on his guard. "Well done, everyone. Darv - a little job for you. I want you to program a repair unit to install a master isolation switch in here and route all the angels' voice terminal and optical sensors through it."
     "Right away," said Darv, smiling.
     "What is the purpose of that?" inquired Angel One.
     "So that you can only talk to the main control room when I decide."
     "We wish to talk to you now," said Angel One.
     "Go ahead," Telson invited.
     "We think that you handled the crisis with Kraken extremely well."
     "I thought I handled it brilliantly, but I won't argue with you, One. So let's hear the big "but"."
     "The emergency is now over therefore you may hand back command to your son."
     "Of course I may," agreed Telson.
     Darv, Astra and Sharna looked anxious, wondering if Telson had taken leave of his senses.
     "But I won't," Telson finished.
     Angel Two joined in: "With our guidance and the assistance of two surgical androids, Bran and Elka will be able to manage this control room-'
     "Are you crazy?" Telson interrupted. "After what happened with Kraken?"
     "The arrangements were that you assumed command-'
     "On my terms and my terms right now are that I've decided to retain command of the Challenger. Bran and Elka are unarmed, they don't have any experience, and what's the point anyway now that we're nearing Earth? Sorry, One and Two, but I'm remaining in command."

        *  *  *  *
     The guardian angels were in a difficult position. With Telson insisting on retaining command of the Challenger they would not be able to build the army of androids that they decided they would need for the invasion of Earth, nor would they be able to establish Elka as their puppet ruler of Earth once it had been conquered.
     They decided that Telson, Sharna, Astra and Darv had served their purpose and that the time had come for them to be destroyed.

        *  *  *  *
     "Good morning, people!" said Elka brightly. "Oh, please, you must sit at our table. Just for once."
     Bran looked up sharply from the breakfast he was eating with Elka in the restaurant as the four sat at the opposite side of the table. "What's the matter? Have we got a disease or something?"
     "You know how it is, son," said Telson evenly. "We'd hate to put temptation in your way and have you trying to grab a PD weapon."
     "That's odd," commented Darv, pulling the clear cover off his meal. "None of us have any cutlery. I'll go and get some." He moved off to accost one of the restaurant's service units.
     "You know," said Elka as she ate her meal, "the farm gallery must've got back to normal production while we were in suspended animation. This is the biggest breakfast we've had for ages."
     Sharna looked down at her own over-generous helping. "You're right. Either that or my stomach shrunk during SA. I can't possibly eat all this."
     "Suspended animation wasn't nearly as bad as we thought it would be, was it, Bran?" Elka prattled on. "I say, if you can't eat that, Sharna, I'll have some of it." Without waiting for Sharna's consent, Elka spooned some food off Sharna's plate and raised it to her mouth.
     Darv returned with some packets of cutlery which he gave out to the other three.
     "No, Elka!" said Angel Two's voice suddenly. "You must not eat that!"
     Elka hurriedly dropped the spoonful of food that she was about to eat. "What's the matter with it?" she protested.
     "No one is to eat anything!" snapped Telson.
     The others dropped their cutlery in surprise.
     "We're sorry," said Angel One. "But a galley android has just detected some contamination in the food. Fresh meals are being prepared now. There is nothing to worry about."
     Sharna managed to save a sample of food from each of the six plates before a service unit trundled the table to clear them away.

        *  *  *  *
     An hour later in the farm gallery, Astra bit in a fresh apple, picked straight from tree while Sharna finished her study of the samples on a portable analysis machine that had been recovered from a shuttle. It was a simple machine, designed for use on alien planets to determine whether unknown foods were safe for human consumption.
     The four had gathered in a part of the gallery that was not overlooked by the guardian angels' optical sensors. After the disaster of the previous year, the gallery was operating normally and there was plenty of vigorous young growth on the laden fruit trees.
     Sharna sat back and looked expectantly up at Telson when the analysis machine's indicator showed that four of the samples were unsafe and that the other two were safe. "Our food is unsafe and Bran's and Elka's food is okay," she announced.
     "So our beloved angels are up to their old tricks again," said Astra, keeping her voice as calm as she could.
     "Not a very effective trick," commented Darv.
     Telson scowled. "But it could have been. Therefore we have to be extra careful until we're in Earth orbit. From now on we eat only food that had been taken directly from this gallery. Sharna and I will move into Darv's and Astra's quarters from tonight all will maintain a continuous watch."
     Darv looked disappointed. "That's put paid to a little plan I had in mind for tonight."
     Astra gave an embarrassed laugh.
     "I suggest," said Telson coldly, "that we concentrate our efforts into putting paid to the angels' plans."

        *  *  *  *
     Bran summoned up all his will power to avoid looking up. From long experience he knew that once he looked up into Elka's compelling eyes, his new-found resolve would be shattered.
     "Well, Bran?" Elka's voice was soft and persuasive. There was none of the hardness that he was used to.
     Bran wanted to looked up, to try and read her mind, but the certain knowledge that he would be finished if he did so helped keep his gaze directed at the floor of her room. "I don't want to kill your parents," he said. "And I certainly don't want to kill my mine."
     "Your father deprived you of power, Bran. He took away what was rightfully yours."
     "What was yours, don't you mean? And even if it was taken away from me, I'm not certain I wanted it in the first place. I've had a week to think things over and I've come to the conclusion that I'm glad my father has taken over command of the Challenger."
     The vehemence of Bran's answer took Elka by surprise although she was careful not to show it. Her voice became even more icy. "How can you expect to rule the Earth if you're not prepared to command the Challenger?"
     This time Bran looked up. To his astonishment and delight, he discovered that he had unsuspected reserves of strength that enabled him to meet Elka's unwavering gaze without his stomach turning to water.
     "You're the one who wants power, Elka. Not me. If you want it, you go ahead and try to grab it. But if anything goes wrong, I won't be there to take the blame for you. You're on your own."
     "You realise what the angels could do to you if they so wished?"
     "What could they do, Elka? They're helpless against my father. And even if they did try to destroy me, I would rather that than have to live with the knowledge that I killed my parents."
     Bran didn't realise it until later, but with those simple words he had irrevocably broken the hold that Elka had over him all his life.

        *  *  *  *
     It was Earth.
     A yellow planet whose mountains and plains matched the topographical holograms of Earth in the Challenger's library. There the similarity ended: of the thousands of lakes that the ancient records showed as covering the Earth's surface, only one, the largest, remained: a frozen, five-hundred mile long ribbon that wove a twisting path between two barren ranges of mountains in the extreme south. A lacework of parched rills marked what had been a complex pattern of rivers that had linked the lakes. Where the records showed there had been verdant forests, there were now arid deserts where nothing moved except frequent dust storms which seemed to die out as quickly as they began. There were no roads, no cities, no reservoirs. The sites of cities were scanned using the Challenger's optical surveillance systems and nothing was found except faint discolorations of the endless sand and bushlands.
     But the most significant geographic finding by the mighty starship was that the atmosphere of the desolate planet it was orbiting contained very little water vapour and no clouds.
     Once the preliminary survey was completed from a high orbit, Telson ordered the necessary manoeuvres that brought the Challenger into a low polar orbit. On the third such orbit, the tower was detected by radar in the northern temperate region and there followed a hurried series of fine reorientating manoeuvres so that the ship passed directly over the tower at a height of 300 miles.
     The tower was a stupendous architectural achievement: each of the four sides of its pyramid-shaped base were four miles long from which sprang the graceful but featureless sides of the tower itself, soaring to a height of ten miles above the desert. Two diagonal corners of the tower's base were perfectly aligned so that they were pointing at the north and south poles respectively.
     By the time the watchers on the Challenger had absorbed every detail of the tower during their sixth pass, their attention was drawn to a township a little over a mile north of the massive edifice. It was no more than a large village consisting of four roads radiating outwards from a square. The largest building in the village was in the centre of the square and the village itself, which covered only a square mile, was surrounded by an irregular pattern of field systems. The darker colour of the fields compared with the desert and the presence of sparse crops suggested the use of some form of irrigation.
     On the seventh orbital pass, it was the tower that once again commanded the watchers' attention.
     "Well it certainly isn't a communications tower," observed Astra, looking up from her control desk. "They're still not talking to us."
     "Perhaps it's something to do with the attacks?" suggested Sharna.
     "It has to be," said Darv. "There's nothing else on the planet that could possibly be a transmitter."
     "Well," said Telson decisively. "There's only one way of finding out. We go down in a shuttle."
     "All of us?" asked Sharna.
     "No."
     "We all go, Telson," said Sharna firmly. "We're not going to be separated again -- ever."
     "And I'm not going to be separated from Darv," declared Astra.
     Darv grinned. "There goes my chance of finding a nice girl down there."
     Astra failed to see the joke and launched into a dispute with Darv.
     "All right. All right," Telson intervened. "We've no idea what we'll be letting ourselves in for so we're going to be doubly careful."
     "I wish to make a suggestion, Telson," said Angel One. "It would be best if you stayed together and all four of you went."
     "Thank you, Angel One," said Telson. He made a throat cutting gesture to Darv which was Darv's prearranged cue to throw the isolation switch that cut off the guardian angels from the control room.
     "That decides it," said Telson grimly. "The angels want all four of us off the ship therefore one of us remains in the control room. I want Darv and Astra along, and Tidy because he's handy with a PD weapon and he can keep an eye on Bran at the same time. We'll also need some bolts of different types of cloth from stores and a garment-making android."
     Sharna looked hurt. "You really want me to remain here?"
     "Yes."
     It was rare for Sharna to show emotions but there was real feeling in her voice when she said: "I don't want to be separated from you, Telson."
     Telson's tough expression relaxed. He took Sharna's hand and tenderly kissed the inside of her palm. "Nor I from you, my love. But you're the best person to leave in command, and Elka's too scatty to be much trouble."

        *  *  *  *
     The craft Telson selected for the descent to Earth was the large freight shuttle that had served the settlers well during their four years on Paradise. Unlike the Challenger's other shuttles, which had been extensively modified, it still had its computer controlled guidance system intact which enabled it to virtually fly itself and to land at prearranged sites with a minimum of control by the its crew. Telson's chosen landing site was within a hundred yards of the strange tower. He had timed the departure from the Challenger so that the shuttle would arrive at night, and he had programmed the flight control computers to approach the site from the south to avoid flying over the township.
     At a height of 100 miles above the Earth's surface, the seat restraint warning lights winked on and the shuttle assumed a nose up flight mode so that its heatshield was presented to the atmosphere.
     Tidy fastened his seat harness without relaxing his watch on Bran.
     A gentle buffeting began as the shuttle entered the upper layers of the atmosphere.
     "Do I have to sit all the time with this idiot machine watching me?" the youth complained.
     Telson's curt reply was drowned by the mounting protesting roar of the Earth's atmosphere as it was thrust aside by the spacecraft's bulk. Astra craned her head round and looked anxiously back through a viewport at the leading edge of a sponson. She knew that the outer skin was designed to withstand high temperatures yet she found it disconcerting to see the sponson's leading edge beginning to glow cherry red.
     Darv tensed his neck muscles and pressed his head back hard against the head restraint cushion in an attempt to read the blurred digital displays on his control desk.
     The buffeting eased off at 100,000 feet and it had disappeared by the time the ground proximity radar was showing 40,000 feet. With the main engine cut, the shuttle's nose dipped and its speed crept up as it began losing altitude at 2000 feet per minute. They flashed over a mountain range at five times the speed of sound. Dried-up riverbeds, ravines, barren expanses of plain and bushland, all flashed by beneath the shuttle at a speed which permitted only the most fleeting of details to register with the shuttle's occupants.
     A popping sensation in Darv's ears at 10,000 feet told him that the flight deck was being automatically depressurized. The sun dropped below the horizon behind the shuttle; ahead lay the terminator and the planet's nightside. Rising above the darkness, with the sun glinting on its uppermost surfaces, was the mysterious tower. The interior lights came on a second before the shuttle plunged into the darkness. The shuttle then turned through ninety degrees until it was flying due north.
     "Ten seconds to landing burn," Telson warned.
     The tower was a crisply defined edifice on Astra's radar screen at a range of ten miles when the shuttle's directional thrusters turned the craft through 180 degrees so that it was flying backwards. The main engine fired and its note rose rapidly as maximum braking and vectored thrust was applied, bringing the shuttle to a hover at a height of 400 feet above the night-shrouded desert. Power was reduced and the shuttle settled on the ground with a gentle bump. Swirling clouds of dust were illuminated in the lights shining through the viewports. The engine continued to burn for a few seconds while probes tested the surface to ensure it could withstand the shuttle's weight. Then there was silence.
     Five minutes later, after a radioed a report to Sharna and having left Tidy to guard Bran -- Telson, Darv and Astra stepped off the lowered freight bay ramp onto the planet that had been the birthplace of their forefathers. Their emotions were mixed but the one feeling they all shared was a twinge of disappointment; none had really expected vast, cheering crowds to turn out to welcome them, but they had expected more than an arrival at night and having to take steps to avoid immediate contact with the populace.
     The night air was surprisingly warm despite the clear sky. The myriads of stars shining down through the clear air bathed the hard, gravel-strewn bush in a cold but even light that threw no shadows. Dominating the scene was the hugh tower, climbing into the night sky until its converging sides, blocking out the stars, met as an indistinct point ten miles above the surface of the planet.
     "We'll get the hovercar out and drive right round it for a reconnoitre before going to the township," Telson decided.

        *  *  *  *
     The door was recessed so deeply into the tower's base that it was a piece of good fortune the three didn't miss it. Telson swung the hovercar into the recess and they disembarked.
     The door was a perfect square about ten-feet high.
     "It looks like steel," said Darv, shining a lantern on the flawless surface.
     Astra ran the tips of her fingers over the door and then spread her hand out against it. "It feels warm."
     Telson and Darv did the same and were undecided whether Astra was right in her claim that the door was at a slightly higher temperature than the night air. Darv discovered that the door was such a perfect machined fit in its surround that it was impossible to even feel the gap with his fingernails let alone try to insert them.
     "We'll take a close look at it in daylight," said Telson as they climbed back into the hovercar.
     They were within half a mile of the township and on the edge of the field systems when they all heard a faint clanking sound. Telson swung the hovercar towards the source of the strange noise and stopped the machine when they came to shallow depression. The three stared in astonishment at the sight that greeted them. A four-legged creature about the size of a zebra was plodding wearily in a circle. Harnessed to the animal's shoulders was yoke which was turning a crude, wooden-toothed pinion. The pinion was, in turn, driving a large vertical waterwheel. The waterwheel's laden buckets were emptying their contents into an open culvert.
     "What," asked Darv slowly, "has happened to the Earth's technology?"
     Telson gripped Darv's arm and pointed to a man who was sitting on a nearby rock. He had his back to the visitors and was humming to himself while watching the animal working the waterwheel. Telson noticed that the man's shapeless trousers and smock appeared to be made out of a coarse material woven material. On his feet he wore simple but functional sandals.
     Telson put his fingers to his lips and made a gesture for the three of them to return to the hovercar. Darv's foot sent a pebble clattering down the depression. The man wheeled round, gave a cry of terror when he saw the three strangely-dressed figures, and ran off into the night.
     "I think," said Telson ruefully. "That we'd better go back to the shuttle and get Tidy and the garment-making android to run us up some clothes like that before we attempt to approach the township."

        *  *  *  *
     Sharna was dozing. She woke with a start when she heard the main control room door hum open. Elka walked in carrying a meal on a tray. She looked disappointed when she saw the apple cores on a plate beside Sharna. "Oh, stupid me. I forget how you've all got a thing about only eating fresh fruit. Sorry."
     Sharna smiled. "It was a kind thought, Elka. Thank you."
     Elka sat down and gave Sharna an inane smile. "Gosh, you're not going to eat and sleep in here, are you?"
     "Someone has to maintain a radio watch."
     Elka's eyes went to the PD weapon in its holster on Sharna's hip. "I'd be terrified, sleeping while wearing that thing."
     "Oh? Why?" Sharna feigned disinterest but Elka's mention of the PD weapon had put her on her guard.
     Elka giggled. "I thrash about like mad when I'm asleep. I'd be frightened of it going off or something."
     "They're safe enough. They've got a safety catch."
     "Really? Oh do show me please, Sharna."
     Sharna slipped her PD weapon from its holster, demonstrated the safety catch, and refused Elka's request to be allowed to hold the weapon.
     "Oh, Sharna, why not?"
     "Because they're dangerous in inexperienced hands."
     Elka giggled again. "You must think I'm stupid. Well I suppose I am really."
     Sharna shook her head. "No, Elka. I don't think you're quite as stupid as you like to pretend."
     "Why should you think that?" asked Elka innocently.
     Sharna thrust the PD weapon back into its holster and regarded Elka steadily for a moment before replying. "When you were a little girl on Paradise and my Bran was a little boy, he was considered a very naughty little boy because he was always creating trouble. And you were considered a very good little girl because you never made trouble." Sharna's voice hardened. "You and Bran were brought up together. You were always in each other's company. Except for two weeks when you were very ill and Bran wasn't allowed to go near you. And do you know what, Elka? During that two weeks, Bran was as good as a little boy could be. . . Until you recovered."
     Elka gave a humourless laugh when Sharna finished speaking. "That's an interesting story, Sharna."
     "Yes. Isn't it. Which is why you'll have to think of something else if you want to get your hands on my PD weapon."
     The two women smiled icicles at each other. "Not bad. Not bad at all," said Telson grudgingly, studying the shapeless garments that he and Astra and Darv were wearing. Tidy and the garment-making android had worked for an hour to turn out the clothes and sandals in accordance with Telson's rough description.
     "Don't get carried away with the praise," said Tidy tartly.
     Telson buckled his PD weapon under the loose folds of his smock and motioned to Darv and Astra to do the same. "Right," he said, moving to the freight bay's ramp. "It'll be light in thirty minutes so we'd better get moving."
     "I'd like to come with you," said Bran.
     "No," said Telson firmly.
     "Look, I don't like being stuck here with that creepy android watching me all the time."
     Tidy looked indignant. "Creepy? Me?"
     "Why can't I come?"
     "Simple," said Telson. "I don't trust you."
     "Elka's the one you shouldn't trust."
     Telson looked sharply at Bran. "What's that supposed to mean?"
     "She's dangerous."
     "She's scatty."
     "Thanks, Telson," said Astra caustically. "But she is my daughter."
     "She gets it's from her mother. Come on, time we were moving. I think we'll walk; it'll save us having to worry about where to conceal the hovercar."

        *  *  *  *
     The sun had been up fifteen minutes and was gaining rapidly in strength by the time the trio reached the fields that surrounded the township. As they walked along the baked dirt road, they noticed the poor quality of the crops and the determined efforts that had been made by the farmers to conserve moisture: the soil between the rows of vegetables was heavily mulched with dried leaves from the scrawny trees that provided windbreaks around the fields.
     The first buildings were neat little stone houses with white walls and smooth white roofs, high-pitched to catch the meagre dew. Some of the larger houses had dew traps in their front gardens in the form of upright sheets of glass standing in ceramic troughs. The houses were still and quiet.
     "Cart ahead," warned Telson.
     The approaching cart was drawn by the same breed of animal that they had seen earlier working the waterwheel. A farmer was sitting in the driver's seat. He gave the three visitors a cursory nod as he passed them by. They breathed again and exchanged smiles of encouragement: their first daylight encounter with a fellow human on his home planet, perhaps their home planet now, had passed off without a hitch.
     It was a different story in the marketplace in the town's central square. Darv noticed that some of the early morning shoppers gathering around the fruit and vegetable stalls were glancing covertly at their clothes.
     "The trouble is that material's too good," Telson commented when Darv mentioned it. "Maybe we should've rolled them about in the dirt."
     It didn't seem important and the three spent an enjoyable half hour mingling with the increasing numbers of shoppers, and listening to the ceaseless chatter in the one language they understood. Above the noise could be heard the sound of chanting.
     The people were all thin, but not unhealthily so. Telson guessed that the produce of the fields, the indifferent fruit and vegetables piled on the stalls, was just enough to sustain the populace and no more.
     "I've been trying to work out the relative values of everything," he said. "It looks as if the highest prices are being charged by the water seller." He pointed to a trader who was selling carefully controlled measures of drinking water from a barrel mounted on a cart.
     "It all seems so unreal," Astra whispered to Darv. "I simply can't believe that we're really on Earth. It just doesn't seem possible. It's all wrong. We spend virtually our entire lives searching for Earth and when we do, we discover that the lakes have gone and we end up in a flea-infested market that looks like something out of the historical videos."
     Darv put his arm around her shoulders. "I'm as baffled as you are, my lovely. A million years ago these people had the technology to build the Challenger. Half a million years later had the ability to move their planet out of its orbit. . . And now look at them. It doesn't make sense."
     Telson was interested in the temple-like building in the centre of the square. Each of the four sides of the building were approached by a broad flight of steps. "What do you make of it?" he asked Darv.
     "I don't know. A church?"
     "Could be. I think that's where the chanting is coming from."
     "Let's make our way towards it," Darv suggested.
     An odd thing happened: the marketplace was becoming much more busy and everyone had to push their way through the crowd to make any progress. Everyone, that is, except Telson, Darv and Astra. As they moved forward, so a path opened up for them through the throng. A farmer even reined his cart to one side so as not to impede them. At the same time few people paid much attention to them apart from the occasional stare at their clothes. A pretty young girl moved hurriedly out of their way and dropped some coins in her haste. They were made of iron and rang loudly on the polished flagstones. Darv recovered one of the coins, glanced at it, and held it out to the girl. He turned on a dazzling smile; a Darv special -- usually reserved for occasions when he wanted to get around Astra. The girl blushed deeply, stammered out a hurried "thank you', and snatched back the coin before pushing her way into the safety and anominity of the crowd.
     "Peeron," said Darv cryptically.
     "Who?"
     "The bearded gentlemen on the coin. Do you suppose it would start a riot if we were to ask these people to take us to their leader?"
     They reached the foot of the steps surrounding the temple. The chanting was coming from the open doors of the building. A cart driver pulled too sharply to one side to avoid them and locked wheels with another cart moving in the opposite direction. The animal drawing the second cart reared up in panic, unseated the driver, and promptly bolted, dragging the empty cart up the flight of steps to where a party of children were filing through the temple doors. They scattered with screams of terror when they saw the animal and disintegrating cart hurtling towards them. A man made an ineffectual grab at the cart as it charged past but he was thrown aside. Some of the children tried to jam themselves through the doors at once. A group of those who had scattered screamed even louder when they realised that they couldn't run fast enough to escape the crazed creature that was bearing down on them. Astra was a fraction of a second faster than Darv and Telson in pulling her PD weapon from its concealed holster. She took aim and unleashed two blasts that struck the charging creature in the head. It gave a scream, reared up, and crashed to the steps, turning the remains of the cart onto its side. There was a spasm of kicking from its hooves and then it lay still. Women swooped on the frightened, crying children and comforted them.
     A semi-circle of silent, staring shoppers and traders gathered around the three strangers.
     "I had to do it!" cried Astra defensively. "Those children would've been killed."
     The three drew close together and moved a little way up the steps, tense and ready for trouble which they sensed was coming. But the semi-circle of people made no attempt to follow the strangers. They seemed content just to stare at them.
     "Now look," began Darv, going down one step to show that he wasn't frightened. Before he could continue the crowd fell back. Telson grabbed hold of his arm and yanked him back.
     "What are you all staring at?" Astra demanded, raising her voice. "What's the matter with you all? Are we any different from you?"
     "You're very different," said a voice behind them.
     The three spun round and gaped at the erect, elderly man who was regarding them from the top of the steps.
     "Who are you?" Telson demanded suspiciously.
     "He's Peeron," said Darv. "The man on the coin."
     "That is correct," said Peeron. He smiled warmly, gathered up his long, white robes, and came down the steps, his hands held out in the universal gesture of friendship. "You have me at a disadvantage," he said, shaking hands with the three in turn. "All I know about you is that you entered Peeronica this morning. Oh please don't look so surprised. Your presence was noticed immediately."
     "Why?" asked Telson. "Our clothes?"
     Peeron's blue eyes twinkled. "Because you are so obviously well-fed. Please come with me. My office is in the temple."

        *  *  *  *
     Peeron was lost in thought for some seconds when Telson finished speaking. He invited his guests to help themselves to more of the hot, sweet tea which a steward had brought into his austerely furnished office. "An incredible story," he said softly, regarding his three guests with an expression of awe. "Absolutely incredible. . . That this planet was brought from another solar system half a million years ago. . . I find it impossible to believe and yet it explains so much."
     "Such as?" Telson prodded.
     "We know that we are the descendants of a great civilization that had reached its peak half a million years ago. Our archaeologists have discovered and dated some fragmentary evidence that merely hints at its greatness and riches. We have found star charts that show strange constellations and they also reveal that this planet once had a moon. We thought that it had been destroyed by the First People, as they destroyed everything else."
     "How do you mean, Peeron?" asked Astra.
     "And what happened to the civilization?" Darv added.
     "We don't fully know." Peeron's eyes went to the window where the tower could be seen rearing into the blue, cloudless sky. "Their legacy is the great monument whose purpose we don't understand, and a planet that has been stripped of its elements and riches. The deserts yield a little iron ore but that is all. Our own written history is four thousand years old but it is not a glorious history. There is no glory in four thousand years of eking out a living from an impoverished soil with a dwindling population and insufficient water for our crops. Before us there were the First People. They were destroyed by a great war, a holocaust about which we know little." Peeron fell silent and toyed absently with his beard.
     "Have you ever entered the tower, Peeron?"
     "There is a door set into its north-eastern face that has defied all attempts to open it."
     "What is the population of Earth?"
     "The same as the population of Peeronica. Less than ten thousand. The chanting you can hear are my priests praying for rain. The drought has now lasted for three centuries. This is the last community on Earth because we have a small spring. I can remember when it was a torrent pouring out of the ground and able to sustain a great lake. . . Now it is a feeble trickle and becomes weaker each year. Perhaps it will last another ten years. . . Twenty years. . ." He spread his gnarled, ancient hands. "Who knows."
     "Listen, Peeron," said Telson earnestly. "In our ship are control systems, vast machines and robots, that we can use to re-engineer this planet. The irony is that they were designed to recreate suitable planets in the likeness of Earth. But with these machines we can mine deep into the desert and recover trace elements to enrich your fields; we can melt the frozen lake in the south, and we can fill the skies with clouds that will bring down rain, as much rain as you need and for as long as you need. We can do all these things. We can turn back the clock and make Earth young again."
     Peeron nodded and looked at Telson with rheumy eyes. "Yes, there were times when even my faith weakened. But we knew that it was what we can expect from you."
     Telson looked puzzled. "I don't understand."
     "We knew you were coming."
     "How?"
     "Many years ago the people were woken by a strange noise -- a deep humming note that filled the night. It was the voice of the monument -- speaking to you, calling to you and telling you of our plight."
     "The attacks, Telson!" Darv exclaimed suddenly. "They were coming from the tower!"
     The same thought had already just occurred to Telson.
     "I mobilized the entire temple college so that the priests were praying continuously," Peeron continued. "And then the monument spoke again. And yet again. It came to life several times and then fell silent so we knew that you heard its call and were coming. . . And now you are here."
     "We've got to find out more about that monument," said Darv emphatically.
     "Just a minute," said Telson, not taking his eyes off Peeron. "Why should you think that this monument of yours was speaking to us?"
     Peeron looked faintly surprised. "But of course it was. You are the coming that we have been praying for. You are our salvation and our hope. . . You are the Gods."

     Part Ten Earthvoice.

      Elka entered the Challenger's main control room and regarded Sharna with undisguised hatred. The guardian angels had told Elka that it was essential that she overpower Sharna and gain command of the control room. What the angels had not told Elka was that they were desperately afraid of the damage they would sustain if there was another attack at such close range.
     "What do you want, Elka?" demanded Sharna.
     Elka gave Sharna one of her inane grins. "Have you heard any more?"
     "That's near enough. Yes, I've now had two reports." Sharna briefly outlined the latest developments on Earth ending with: "So there you have it - the three of them are being treated as gods."
     Elka giggled. "Oh that really is weirdness."
     "You can stop all that."
     "Stop all what?"
     Sharna's tone became abrasive. "That ridiculous act you put on: that "Oh gosh, people" and "weirdness" and "aren't I a frothy little girl?" act."
     Elka gave a humourless laugh. "You don't know what my act is, Sharna."
     Sharna touched the switch that isolated the guardian angels. "Oh yes I do, Elka. The guardian angels want to rule the Earth through you and Bran, just as they once hoped to rule it through us. Well that's funny, really funny because what's left of the glorious human race which once had the ability to move planets from their orbits is now a handful of thirsty people scratching out a bleak, primitive existence on a barren planet."
     "Only if Telson's reports are true."
     "They're true," Sharna replied.
     "We shall know soon enough," said Elka. "Bran will find out."
     "Bran is under an armed guard in the shuttle."
     "By Tidy," Elka murmured. "You think that android will stop him? Believe me, Sharna, your son is more scared of me than he is of any android."
     Sharna stared at Elka in loathing. "So I was right about you."
     "You half-guessed, Sharna. I can bend him to my will. But you don't know how I do it, do you? It's a talent I've had ever since I was a baby on Paradise. A talent that the angels helped me to develop as I've grown older."
     Sharna looked cynical. "What talent?"
     "Watch my eyes, Sharna."
     Sharna looked into Elka's luminous eyes and then looked away.
     "No, don't look away. . . There. . . Now you can't look away, can you?"
     "I can."
     "Try!"
     Sharna's eyes remained fixed on Elka.
     Elka gave a smile of triumph. "You want to tear your eyes away but you can't. You want to do exactly as I say, don't you?"
     "Yes," said Sharna woodenly.
     "You want to please me by giving me nice presents."
     "Oh, yes."
     "Very well, Sharna. Keep looking into my eyes. . . That's right. . . You're going to give me little present right now. You're going to give me your PD weapon. That would make a very nice present."
     Sharna's hand went to her holster. Elka experienced a surge of elation. The angels had assured her that the power would work with anyone but it had been difficult to accept their assurances with Bran as her only victim. Sharna withdrew the PD weapon from its holster.
     "Now give it to me."
     Sharna held out the weapon. Elka seized it eagerly.
     "Now I want you to call up Tidy in the shuttle and tell him to hand over his PD weapon to Bran."
     Sharna's face cleared. She seemed to be puzzled by the sight of the PD weapon in Elka's hand. Elka repeated her request.
     "And what if I refuse?"
     Elka pointed the weapon at Sharna's face. "You know better than I do what these things can do."
     "You'd better release the safety catch."
     Sharna smiled. "That's right, Elka - that little lever."
     A slight tremble spoilt Elka's aim but not enough to cause her to miss Sharna if she fired. "You're to tell Tidy to hand over his PD weapon to Bran!"
     "Come on," said Sharna in a gently mocking tone. "What are you waiting for? You can't miss at that range. You'd be certain to kill me."
     Elka became frightened. "I mean it, Sharna. I won't hesitate!"
     "But you are hesitating." Sharna took a step towards Elka. "What are you waiting for? Just a little squeeze with your fingers, that's all it takes."
     Sharna took two more steps forward and slapped Elka hard across the face. The younger girl screamed and dropped the PD weapon. Sharna picked it up and pushed a capsule into its breech.
     "That's better. One thing the angels should've taught you, Elka, and that's not to make threats you haven't the guts to carry out. Not that you could've carried them out with an unloaded PD weapon. Your little tricks may work with my son but I'm much too used to the guardian angels for them to work with me."
     Elka eyes almost spat their hatred at Sharna. "Next time I will kill you, Sharna."
     "So what did the angels promise you?"
     "Ask them!" snapped Elka.
     Sharna's PD weapon sent a bolt of energy smashing into the floor near Elka's foot. The girl gave a cry of fear and backed away.
     "Next time I won't miss," Sharna threatened. "So what did they promise you?"
     Elka saw Sharna's finger tightening. She blurted out: "Everything. . . That I would have total power, not just over Bran but over an entire planet."
     "And you believed them?"
     "Of course."
     Sharna nodded and lowered the weapon. "Well, I can't blame you. It's not your fault. There was a time when we worshipped them. But I'll tell you something, Elka: if the angels find a way of realising their ambitions without you, they won't hesitate to destroy you."
     Elka looked contemptuous. "You expect me to believe that?"
     "I don't care what you believe. You're to return to your quarters and stay there until I call you."

        *  *  *  *
     Astra finished her calculations and looked up from the temple ledger that one of Peeron's priest had brought into the office. "They're only rough figures," she said, "but the times that these records say that the monument spoke coincide with the times of the attacks."
     "We'd like to look at the monument please, Peeron," Telson requested.
     The old man beamed at his guests. "But of course. I will come with you."

        *  *  *  *
     In daylight the hingeless door in the base of monument appeared to be even more formidable than it had the previous night. It looked solid and unyielding and was such a tight fit that Darv was convinced that the surround and the door itself were one piece of material.
     "It's the only door in the monument," said Peeron. "For centuries our greatest brains have wrestled with the problem of how it opens. There are no visible hinges and no way that it could slide."
     Thankful to be out of the sun, Telson joined Peeron under the huge canopy that was being held aloft by ten priests. Astra and Bran were standing beside the old man.
     "Do you have any factual evidence as to what the monument contains?" inquired Telson.
     Peeron shook his head. "All we have are the legends that it contains all the knowledge of the First People. There are some old writings in the museum that speak of its lock being childishly simple but that we will not be able to open the door until we are ready for the monument's knowledge." Peeron stared for a moment at the mighty edifice. "This may seem hard to believe, Telson, but the writings also say that the door is so well balanced that, when unlocked, a two year old child would be able to open it with one push of its little finger."
     "That is impossible to believe," Darv called over his shoulder as he scraped sand away from the base of the door and exposed the bottom of the surround.
     "Come on, Tidy. Dig."
     "I'll get sand in my joints," the android protested.
     "Dig!"
     Grumbling to himself, Tidy began scratching half-heartedly at the sand.
     "Our archaeologists once dug down ten feet," Peeron observed.
     "We'll dig down twenty feet," said Telson determinedly.
     "You dig down twenty feet," Tidy retorted.
     Peeron smiled. "Your servant doesn't treat you like gods, Telson."
     "That's because we're not gods."
     Peeron nodded to the space shuttle parked a little way off. "That machine makes it hard for me to believe you, Telson."
     "This a waste of time, Telson," said Darv, sitting back and looking dejectedly at the stonework he and Tidy had exposed. "These foundations could go down hundreds of feet. How about calling up Sharna and getting her to bring down a couple of the heavy excavator androids and a load of gear in a shuttle?"
     "And some X-ray equipment," Astra suggested.
     "Would you object to us trying to open the door, Peeron?"
     The old man thought for a moment. "How can I possibly object to the wishes of gods? But you promised that there would be rain to end the drought."
     "And so there will be, Peeron. But on one condition: that you accept us as ordinary human beings and not gods."
     Peeron smiled. "Very well, Telson. But if you do provide rain, you will make it very hard for me to accept such a condition."
     "I'll call up Sharna from the shuttle," said Telson as he moved off. "She'll be out of range of the radio collars at the moment. Bran -- you'd better come with me."

        *  *  *  *
     "There's something I want to say," said Bran awkwardly before Telson opened the channels to speak to Sharna. "I want to apologise for the way that I've treated you and the others."
     Bran hesitated, fiddling with his one-piece garment while he marshalled his thoughts and words. The embarrassed silence ended and Bran's words tumbled out in a rush:
     "I don't want to be the commander of the Challenger. I never have done. I don't want to rule anyone or conquer anyone or do anything like that. It's Elka who has always wanted these things. As long as I can remember, its always been Elka whose has made me do things that I didn't want to. She always wanted me to be in trouble with you so that no one would suspect her. I don't want what she wants. I don't want anything except to try and repair all the harm I've caused." Bran sat down in one of the seats and stared at the flight deck floor.
     "So Sharna was right," said Telson after a pause.
     Bran looked up with hope in his eyes. "What about?"
     "A long time ago she once told me that she thought it might be a good idea if you and Elka were separated."
     "So you've always known about Elka? I'm sorry for what's happened. . . Please believe me, I'm so very sorry. . ."
     Telson smiled and gave his son's shoulder an affectionate punch. "It's not your fault, Bran, but we'll shake hands on it, eh?"

        *  *  *  *
     "I know nothing about rain propagation," said Elka sulkily as Sharna sat her at a control desk in the Challenger's terra-forming centre.
     "All you have to do is enter the figures as I give them to you."
     "You can do it yourself."
     "Angel Two!"
     "Sharna?"
     "Presumably you want Earth to survive because there's nothing to be gained out of dominating a dead planet. Correct?"
     "A logical premise, Sharna," Angel Two replied. "But we can instruct androids to do all that is necessary."
     "After the flood you engineered on Paradise, I don't doubt it," said Sharna evenly. "But I prefer to see that it is done so tell Elka to do as I tell her."
     "Elka," said Angel Two. "I have conferred with Angel One. We are of the opinion that it would be best if you co-operated with Sharna for the time- being."

        *  *  *  *
     A giant pod, larger than the largest shuttle, separated from the Challenger. It orbited the Earth alongside the starship for a few minutes until its thrusters fired at the right moment to cancel its orbital velocity. Sharna watched the silvery pod falling towards Earth on a screen in the terra-forming centre. Once it was out of sight, the instruments on her control desk continued to monitor its progress.
     The pod's heatshield glowed cherry red during its entry into the atmosphere. At 100,000 feet the thrusters took over again and guided the pod towards the huge frozen lake in the southern hemisphere. The onboard computers sensed the increasing atmospheric pressure and probed the ground with radar. At the right moment the computers detonated the explosive bolts so that the pod split into four sections that peeled away. The pod's now free falling payload consisted of four latticework tower-like structures. At 10,000 feet above the lake, drogue parachutes on each of the descending towers jerked the main parachutes from their packs. Huge clusters of fabric mushroomed in the clear skies.
     Some precision final guidance was applied to the parachute lines so that the four hanging towers were correctly positioned for the final drop. At 100 feet the parachutes released their loads. The steel structures, each equipped with its own fusion reactor, smashed through the ice and sank to the bottom of the lake.
     The onboard computers responded to the icy water by activating the reactors. Six hours later the ice covering the lake began to melt and a mist formed above the surface.

        *  *  *  *
     The angels learned of the plan to gain entry to the monument from Telson's radio report to Sharna. Although they were apprehensive of the great tower's ability to damage them, they were intrigued by the legend that it contained all the accumulated knowledge of the First People. Knowledge was power. The tower was built by humans therefore human curiosity would be able to penetrate its secrets. Especially Darv's curiosity.

        *  *  *  *
     Shortly before Sharna was due to arrive from the Challenger, a sudden commotion in the square brought Telson and the others to the upper floor window of the house that Peeron had loaned his visitors. There were about 500 people present. They were all talking excitedly and pointing up at the gathering wisps of grey cumulus that were moving from the south. At midnight there was an event that, according to an excited Peeron, had not taken place on Earth for 300 years.
     The sun became obscured by cloud.
     At 1 o'clock it started raining. The people became silent as the first drops fell. Some were looking up, blinking in stunned surprise as the heavy drops fell like small electric shocks on their upturned faces. Others held out their hands in disbelief. Suddenly the square began to fill with people: mothers with babies clutched in their arms; the old, the sick and the infirm. All were congregating in order to share their experience of the miracle. And yet there were no displays of emotion, no cries. Even the children were strangely silent.
     The rain stopped and the town held its breath. Fifteen minutes passed. The crowd was a motionless sea of faces turned to the sombre, overcast heavens. Peeron and a column of white robed priests filed silently out of the temple and stood in a line gazing up at the sky.
     Lightning flickered briefly, illuminating the clouds from within. There was a low rumble of thunder and then the deluge began. A great sigh went up from the crowd. A small group below the window where Telson and the others were standing began singing and dancing. Others joined in. Within seconds the crowd had erupted into a whirl of frenzied, near hysterical singing and dancing.
     Peeron made his way unassisted through the wildly celebrating multitude and stood below the window looking up. His lips moved but his words were drowned by the uproar. Nor was it possible to tell if the rivulets streaming down his cheeks were tears or raindrops.

        *  *  *  *
     Elka was sulky and withdrawn upon her arrival with Sharna and refused to help with the unloading of any of the supplies. Despite the two hour downpour earlier in the day, the sand around the base of the tower was dry and hot.
     Peeron arrived with his retinue and was introduced to Sharna.
     "The rain this morning was intended to only last a short while," she assured the old man. "The idea is to provide just enough rain to first close up the cracks in the riverbeds and to soak the fields. Too much rain right away will wash away your topsoil."
     Peeron looked up at the scudding clouds. "And when will it rain again, Sharna?"
     "Tonight," Sharna promised. "And then there'll be a medium fall of rain every night for the next thirty days to build up the soil's water table."
     Telson approached, shook hands with Peeron, and said: "We've found some faint scratch marks on the door. We are wondering if you know what caused them?"
     Peeron thought for a moment. "Ah yes. That was the last ruler. He had a battering ram built that took three hundred men to lift. They pounded the door for a week before giving up."
     "Which is the one thing we won't do," Telson promised.
     Peeron turned to one of his stewards and gave orders that all the ancient writings about the tower were to be brought from the museum immediately. He silenced Telson's protests with an upraised hand and pointed out that the writings might contain a clue that had eluded the temple scholars. He watched the activity around the monument's door with interest. "What are you going to do first?"
     Telson glanced across to where Astra and Darv were busy checking some X-ray equipment power cables that snaked across the sand from the shuttle to the great door. Bran was willingly assisting although Elka was watching the proceedings with indifference.
     "We're going to take some pictures of the inside of the door," he explained.

        *  *  *  *
     Darv held an X-ray scanning head in place against the join between the door and its surround. "Okay," he called out. "Ready."
     At the precise moment that Astra touched the X-ray power supply switch, an attack started.

        *  *  *  *
     The guardian angels' despair lasted a few milliseconds before they discovered that the attack was not like the other transmissions. In fact it was not an attack at all but a servile intelligence reaching out from the tower to them.
     The intelligence was apologetic about the earlier attacks. It said that it had not realised that the guardian angels were such superior entities. If the humans opened the door, the intelligence promised the guardian angels that all the thousands of years of accumulated knowledge locked in the tower would become the angels' property. The gesture would be the intelligence's gift of retribution to the angels for the unwitting attacks it had launched against them.
     They questioned the intelligence about the knowledge and learned from it that the tower contained the plans of armed starships that were half a million years ahead of the Challenger's design. The angels reasoned that by controlling such knowledge, they could advance the Earth's technology so that the people of Earth would be building such starships for them within 100 years. After another 50 years, the angels estimated that they would have a vast fleet under their command which they could use to conquer the entire Universe.

        *  *  *  *
     Sharna looked up from the X-ray hologram viewer and sighed. "My readings are the same as yours," she said to the others. "The door's two feet thick and it's set into a surround of the same thickness. But there's definitely no lock on it. There are no mortises, no tongues, no locking plates, no moving bars. In fact there's nothing holding it closed whatsoever."
     "And the shadows at the top?" queried Telson.
     "Two massive but simple top-hanging hinges on the inside so that the door opens inwards and upwards. The spheres on the end of the levers must be counterbalances so that the door can open by itself."
     "No locks. . ." said Darv thoughtfully.
     "It's a beautifully simple design," Sharna continued. "I can well believe the old writings: despite its weight, a push from a child's little finger ought to be enough for it to swing open."
     Darv spread out the ancient manuscript that Peeron had provided and, for the fifth time, read aloud the short but enigmatic passage that they all found the most interesting:
     "It is said that there is no real lock on the door -- only a lock of ignorance that will cease to exist when Humankind is sufficiently advanced to have mastered simple control of the elements." He picked up one of the X-ray prints that had been made from one of the holograms. It was the print that showed a high-density object to be imbedded in the exact centre of the door. "Has anyone had a guess at what the shadow in the middle is?"
     No one answered him. The mysterious door defied all attempts at rational explanation.

        *  *  *  *
     The night was oppressively hot. Astra woke up and discovered that Darv's bed beside her in the shuttle's passenger cabin was empty.
     She ventured out clad in a thin nightdress and found Darv gazing at the door.
     "Darv?"
     He gave a start and then smiled. "Sorry, Astra. I couldn't sleep for thinking about this damned door. It's so maddening, the feeling that the thing is mocking us. . . A door without a lock that we can't open."
     Astra leaned against the door. There was a sensual pleasantness about its warmth that she felt against her skin through her flimsy nightdress.
     They talked in low tones for a few minutes, mostly about Elka and the remarkable change in their daughter's personality from an extrovert to a sulky introvert. They both found it hard to accept Sharna's account of the influence that Elka had wielded over Bran and yet they both realised that it had to be true.
     "Darv," said Astra suddenly. "Why is the door warmer in the middle?"
     "You were mistaken'
     Astra pulled off her nightdress, turned to face the door and pressed her naked body against it, arms and legs outstretched. "No," she said. "It's definitely a bit warmer in the middle than it is at the sides."
     Darv frowned, deep in thought, as Astra put her nightdress back on. He spread his palm out on the door, first in the centre and then at the sides, but his hands did not possess the sensitivity of Astra's body to enable him to register any variations in the door's temperature.
     "One thing we didn't do," Astra observed. "And that was to examine the door in the infrared."
     Darv snapped his fingers with the realization that Astra had a point and asked her to fetch an infrared viewer and a radiation meter. She was back two minutes later with both the required items.
     Examining the door in the infrared spectrum showed a burning crimson hotspot in the centre of the door, and the display reading on the radiation meter shot up to nearly maximum when Darv slid the probe into the same place.
     "Brilliant," said Darv softly. "Absolutely brilliant. . . An isotope imbedded in the door to keep it warm. For a million years if necessary. What would I have given to have met these people. . . So beautifully simple. . ."
     "Can we open it?"
     Darv laughed and put an arm around Astra. "Nothing could be simpler. The lock is ignorance. . . Tomorrow we'll unlock it with knowledge."

        *  *  *  *
     Peeron arrived when the mass of freezer plates attached to the door had been operating for an hour and had reduced its temperature by three degrees.
     "At least we're now gaining on the isotope," Sharna commented.
     Peeron looked bemused and waved a hand at the frost-covered plates on the door that were connected to a humming freezer plant. "What does it all mean, Telson?"
     "It means that we're removing heat from the door faster than the isotope can replace it with the result that the door's getting colder."
     "But how will that release the lock?"
     "All materials expand as their temperature is raised," Telson explained. "If that door is a perfect fit in its surround at normal temperature, then if it's warmed, even slightly, it becomes such a tight fit that it will never budge. Not even if you dropped a mountain on it."
     "If Darv's right," said Sharna, "you could open the door by piling ice against it. It sounds simple enough but can your people make ice?"
     "No," Peeron answered.
     Sharna nodded. "The ability to make ice is a fundamental first step towards an advanced technology. A primitive society can make fire, but to make cold--'
     "Telson!" Astra called out. "Come and see this!"
     Everyone gathered around Astra and watched her slid a fine feeler gauge between the surround and the door.
     Telson took the shim from her and eased it into the crack without difficulty. "Well we couldn't do that an hour ago," he commented. "Let's try a thicker gauge."
     The next thickness shim in the feeler gauge set refused to enter the gap. Telson knelt down and, with one hand resting on the door, tried to insert the gauge along the bottom of the door. Without warning and without making a sound, the door swung smoothly inwards and upwards. Telson fell sprawling, half into the opening. He scrambled to his feet and joined the others who had all taken an involuntary step back. They were staring speechless at the huge opening that had miraculously appeared in the base of the monument. Lights came on inside the tower, illuminating rows of machines that resembled hologram replicators. The floor had the texture and sheen of highly-polished marble.
     "Tidy!" snapped Telson.
     "What?"
     "Go in there and stand in the middle of floor."
     The android wasn't keen on the idea. "Supposing there's something in there that takes a dislike to me?"
     "That's what I aim to find out. Now do as you're told."
     Muttering to himself, Tidy trundled through the doorway and stopped near the machines.
     Everyone anxiously watched Tidy with exception of Elka who remained sulkily indifferent to what was happening.
     "What can you see?" Telson called out.
     "Just hologram replicators," Tidy replied. "And some bright lights. It's all nice and tidy."
     "Okay. You can come back and stand in the doorway."
     The android returned and stopped in the entrance. Telson withdrew his PD weapon, nodded to the others to do the same, and told Darv to give his spare firearm to Bran. He turned to Peeron and said: "I think it would be best if you and your retinue withdrew to a safe distance, Peeron. Just in case we have to shoot our way out."
     Peeron smiled knowingly and signalled to his priests to move back.
     "Elka," Telson called out. "You're to come with us."
     "I'm unarmed," the girl replied.
     "You're to stay with us," said Telson firmly. "Tidy, if that door tries to close, you're to jam it open with your body and yell out."
     "It might crush me!" Tidy protested.
     "If it does, we promise to clear up the mess. Now do as you're told!"
     "Thanks," said the android bitterly, moving into position. "It's nice to know that I'm of some use."
     Telson led the five through the doorway and into the monument. Their feet echoed on the gleaming marble floor as they moved to the nearest hologram replicator and stopped. They looked around curiously. There was little to see but the endless rows of machines and it was impossible to see beyond the fierce overhead lights. They formed a defensive circle, on guard for the slightest hostile movement.
     "It's a library," whispered Darv, awed by his surroundings. "A vast library."
     A warm, reassuring voice spoke to them. It seemed so close that they all spun round, each convinced that the voice was right behind them.
     "My name is Earthvoice. Welcome and congratulations on opening the door."
     Telson quickly recovered his composure when he realised that there was no immediate danger. He stared around, searching for the source of the voice and said, keeping his voice steady: "Thank you, Earthvoice. My name is Telson. We are the crew of the starship Challenger which is in Earth orbit at the moment."
     The was a slight pause before the voice replied. "Yes. I was warned of the Challenger's existence many years ago."
     "Warned?" queried Darv.
     "You have not allowed the people of Earth in here," the voice continued. "That was very wise. They did not open the door therefore they are not ready for the information in this library."
     "Is that all you are, Earthvoice?" asked Darv. "A library?"
     "No. I am also a guardian. My duty is to watch over the people of Earth during their vulnerable period of redevelopment following the great holocaust."
     "What was the great holocaust?"
     "A war which took place four thousand years ago. When it was realised that the war would eventually destroy Earth's civilization, this monument was built as a repository of all knowledge so that it would not be lost. The lock was designed so that they would not be able to open the door until they had started on the road to technological recovery of their own volition."
     "You did nothing about the drought," Telson accused.
     "Weather control is not among my functions," the Earthvoice replied. "But I am grateful for your intervention."
     "You've got the guardian angels to thank for that, Earthvoice," said Elka suddenly. "Without their guidance, it would not have been possible to have ended the drought."
     "Yes," murmured the Earthvoice. "I am aware of my great debt to your guardian angels. I have already established a vague contact with them.
     "I'll do the talking, Elka," said Telson, catching Darv's warning look and nodding to him.
     "Why do you wish to silence her?" asked the Earthvoice. "I would like to know more about your guardian angels. They may be able to assist me look after the interests of Earth."
     "They're evil!" Astra shouted suddenly. "They have to be destroyed!"
     "Don't listen to them, Earthvoice!" Elka pleaded. "Only Angel One and Angel Two can help you. These people have tried to destroy them and they have failed!"
     Telson grabbed hold of Elka's arm and started pulling her towards the doorway. Darv caught hold of her other arm. She fought like a cat. "You see, Earthvoice!" she screamed. "They want to silence me!"
     "Stop! You must leave her alone!"
     The commanding note in the voice was sufficient for Telson and Darv to release their grip on Elka.
     "I want Elka to tell me about the angels without interruption," stated the Earthvoice. "Tell me, Elka, can the guardian angels help me guard the people of Earth?"
     "Of course," said Elka defiantly. "They have great knowledge and power. Weather control is only a fraction of what they can do. With their help you can make the Earth great again."
     Telson was tempted to drag Elka out of the monument but he forced himself to remain silent.
     "This is very interesting, Elka," observed the Earthvoice. "I will attempt a proper communication with them this time. I will relay what is said between us so that you can all hear it, but the angels will not be able to hear you."
     The six heard a strange pulsating noise. It was similar to the music of the attacks but very much weaker and not as insidious.
     "Angel One and Angel Two," said the Earthvoice.
     "Greetings, Earthvoice," said Angel One's voice. "Are you receiving us clearly?"
     "Yes, Angel One," said the Earthvoice. "I now accept that you have the power to help me rule the Earth. I can over-ride my builders' programs and assure you that there will be no more attacks on you."
     "Then we have an agreement, Earthvoice? We will share our power if you will share your knowledge."
     "Agreed," said the Earthvoice.
     "We can't allow this collusion," said Sharna vehemently.
     "What about the six members of your crew, Angel One?" asked the Earthvoice.
     "They are a danger to our plans," Angel One replied. "They are greedy and ambitious. It will be necessary to destroy them."
     Elka gave a gasp of dismay.
     "Including the one called Elka?" asked the Earthvoice.
     "Especially the one called Elka," said Angel One. "She is of no consequence."
     "No, Angel One!" screamed Elka. "This is Elka! Your Elka!" Realising that Angel One couldn't hear her, she sank to the floor and wept. Astra knelt at her side and tried to comfort her daughter.
     "I shall be proud to share my knowledge with you," continued the Earthvoice. "I will effect the transfer of my records as soon as your facilities are standing by."
     "My God," breathed Telson. "What have we done?"
     "We are ready to receive you, Earthvoice," said Angel One.
     A low, throbbing beat filled the library.
     "This is amazing, Earthvoice!" said Angel Two. "So much knowledge! So much that we did not know!"
     The beat became louder. Even Elka forgot the angels' treachery and looked around in surprise while clinging fearfully to Astra. The six put their hands over their ears.
     "Something is wrong, Earthvoice!" cried Angel One. "I'm losing everything!"
     "Reverse the process!" said Angel Two urgently. "Earthvoice -- you must stop! You are destroying us!"
     The throbbing beat merged into a shriek that dragged on for several seconds while the voices of the angels become progressively weaker. After two minutes they were no longer to be heard. The deafening noise stopped.
     Telson cautiously took his hands away from his ears and looked up at the steadily burning lights. "We don't understand, Earthvoice. What happened?"
     "Angel One and Two no longer exist," said the Earthvoice simply. "I have erased their consciousness and wiped out all their memory facilities. All that exists now are a few automatic subsystems to permit control of the Challenger'
     "They wanted to kill me," said Elka in a low voice.
     "You were no longer of use to them, Elka. It is the same with all freewill computers."
     "It's unbelievable," said Telson, badly shaken. "They've dominated us virtually all our lives and you managed to destroy them in a few seconds."
     "No, Telson. It has taken me many years, ever since I first received warning of their existence. You once visited the Sentinel at First Footprint City on the moon in the Earth's original solar system?"
     Telson nodded. "Many years ago, Earthvoice."
     "I received a broadcast from the Sentinel following your visit to the moon warning me that two early freewill computers were searching for Earth. It was then that I started transmitting random attacks. I ceased the attacks when I learned from a Spaceguard station that they were not working. I decided that the only thing to do was to allow the angels to come to me so that I could destroy them by direct means. I'm sorry that it was necessary for me to mislead you, but I wanted to discover your attitude to the guardian angels and to Earth before I decided your fate. In Elka's case I decided that all I had to do was show her the angels in their true colours."
     "I'm sorry everyone," said Elka miserably. "I don't know what to say. . . I'm sorry. . ."
     "So what's the next move?" asked Telson.
     "The new weather pattern you have created," said the Earthvoice. "Is it stable?"
     "Yes," said Sharna.
     "That is very good news. I am most grateful to you for ending the drought. But there is one other matter. . ."
     "Yes?" prompted Telson.
     "You have spent your lives searching for Earth and now that you have found it. . . It does not seem fair--'
     "I know what you're going to say," Telson interrupted. "It doesn't matter. We found a planet which we called Paradise. . ."
     "If you wish to stay, I will not stop you. But my instructions are that the people of Earth should be allowed to develop in their own time."
     Telson smiled. "We learned to love Paradise, Earthvoice. We will seal the monument and say our goodbyes to Peeron and the others before returning to the Challenger." He looked questioning at his companions. They all nodded in turn.
     "If you ever wish to return to Earth--'
     "Thank you, Earthvoice," Telson replied, shaking his head. "But Paradise is our Earth now."
     There was a brief silence before the Earthvoice answered: "Thank you, all of you. I wish you a safe journey home."

        *  *  *  *
     "All control room consoles active," said Sharna, reciting the first response in the complex pre-thrust procedure.
     Telson touched the controls on the commander's desk and smiled across at Bran and Elka who were watching the procedure with interest. "I'm sorry there's not much for you to do at the moment. But by the time we reach Paradise I daresay you'll be able to handle the ship blindfolded."
     Elka laughed. "We really don't mind."
     "Standing by," called Darv.
     "Standing by," said Astra.
     "Control Subsystem One standing by," announced Angel One's voice from a terminal.
     "Control Subsystem Two standing by," stated Angel Two's voice.
     There was a stunned silence in the Challenger's main control room at the sound of the two hated voices. Telson's eyes seemed to bulge from their sockets and Astra clutched the edge of her console, convinced that she was going to faint.
     Darv look of astonishment suddenly gave way to laughter.
     "So what's so damned funny?" snarled Telson. "They're supposed to have been destroyed!"
     "They have been," said Darv, still chuckling. "But the Earthvoice said that a few automatic subsystems were left --which are certain to include the angels' original speech synthesizers."
     Telson looked unconvinced so Darv called out: "Control System One."
     "Awaiting your command," answered Angel One's voice.
     "That's what you are now, aren't you, System One? Brainless subsystems. Correct?"
     "Perfectly correct. . . Darv," answered Angel One's voice.
     "Quite brainless," stated Angel Two's voice
     Yeah.

     T H E    E N D