Sam had nodded. "Yes, sir. Do you mean you can make other brains exactly like mine?"

"Technically, the control computer can duplicate ypur design," DeMatre had answered. "It won't be just like your brain. Too many random factors in any really advanced mechanical mind unit. But with similar capabilities. That's why you're worth more money than this whole project without you. You're worth quite a few million dollars, and it's up to you to see that valuable property like that isn't destroyed. Right, Sam?"

Sam had agreed and been shipped back to the Moon, along with the first of the Mark Three robots. And maybe his trip to the research center had been of some use, since the new Mark Three models worked as well as their limitations permitted. They were far better than the preceding models.

Maybe he wasn't valuable enough to men for them to come for him now. But by DeMatre's own words, he was one of their most valuable possessions. If it was up to him to see that he wasn't destroyed, then it was up to him also to see that he wasn't lost to men.

If they couldn't come for him, he had to get to them. The question was: How?

He couldn't project himself by mind power like John Carter. He had to have a rocket!

With the thought, he went dashing out through the entrance and heading toward the old wreck. It stood exactly as it had after the landing that had ruined it, with half its hull plating ripped off and most of its rocket motors broken. It could never be flown again. Nor could the old supply capsules. They had burned out their tubes in getting here, being of minimum construction. There wasn't even s.p.a.ce inside one for him.

Sam considered it, making measurements and doing the hardest thinking of his existence. Without the long study of all the technical manuals of the domelibrary, he could never have found an answer. But eventually he nodded.

A motor from the big ship could be fitted to a capsule. The frame would be barely strong enough. But the plating could be removed to lighten the little ship; Sam needed no protection from s.p.a.ce, as some of the cargo had required.

And the automatic guidance system could be removed to make enough room for him. He could operate it manually, since his reaction and integrating time were faster than that of even the system.

Fuel would be a problem, though there was enough oxygen in the dome storage tanks. It would have to be hydrogen, since he could find rocks from which that could be released by the power of the generator. Fortunately, lunar gravity was easier to escape than that of Earth.

He went back to the dome and found paper and pencil. He was humming softly to himself as he began laying out his plan. It wasn't easy. He might not be skilled enough to pilot the strange craft to the station. And it would take a great deal of time. But Sam was going to the men who wouldn't come to him!

4.

It takes experience to turn engineering theory into practice. Almost three years had pa.s.sed since Sam's awakening before the orbital station swam slowly into view before him. And the erratic takeoff and flight had been one that no human body could have stood. But now he sighted on the huge metal doughnut before him, estimating its...o...b..t carefully. There were only a few gal- lons of fuel remaining in the tanks behind him, and he had to reach the landing net on the first try.

His first calculations seemed wrong. He glanced down at the huge orb of Earth and flipped sun filters over his eyes. Something was wrong. The station was not holding its bottom pointed exactly at the center of Earth as it should have done; it was turning very slowly, and even its spin was uneven, as if the water used to balance it against wobbling had not been distributed properly.

Beside it, the little ferry ship used between station and ships from below was jerking slightly on the silicone-plastic line that held it.

Sam felt an unpleasant stirring in his chest where most of his brain circuits lay. But he forced it down and computed his blast for all the factors. He had learned something of the behavior of his capsule during the minutes of takeoff and the later approach to the station. His fingers moved delicately, and fuel metered out to the cranky little motor.

It was not a perfect match, but he managed to catch himself in the net around the entrance to the hub. He pulled himself free and began scrambling up to the lock as the capsule drifted off. A moment later, he was standing hi the weightlessness of the receiving section. And from the sounds of his feet, there was still air in the station.

He froze motionless as he let himself realize he had made it. Then he began looking for the men who should have seen his approach and be coming to question him.

There was no sound of steps or of any other activity, except for his own movements. Nor was there any light from the bulbs above him. The only illumination was from a thick quartz port that faced the sun.

Sam cut on the lamp built into his chest and began sweeping the sections of the hub with its light. Dust had formed a patina here, too. He sighed softly into the air. Then he moved toward the outer sections, his steps determined.

Halfway down the tube that ran from the hub to the outer hull, Sam stopped and cut off his light. Ahead of him, there was a glow! Lights were still burning!

He let out a yell to call the men and began running, adjusting for th^j increasing feeling of weight as he moved outwariSv'Then he was under the bulb.

He stared up at it-a single bulb burning among several others that were black, though they were on the same circuit. How long did it take for these bulbs to burn out? Years surely, and probably decades. Yet most of the station was in darkness, though there was still power from the atomic generator.He found a few other bulbs burning in the outer station, but not many. The great reception and recreation room was empty. Beyond that, the offices were mostly open and vacant. Some held a litter of paper and other stuff, as if someone had gone through carelessly, not bothering to put anything back hi place. The living section with its tiny sleeping cubicles was worse. Some of the rooms were simply bare, but others were in complete disorder. Four showed signs of long occupancy, with the sleeping nets worn almost through and not replaced. But nothing showed how recently they had been left.

He went through another section devoted to station machinery and came to a big room that was apparently now used for storage. Sam had seen a plan of the station in one of the technical books in the dome. He placed this room as one designed as a storage for hydrogen bombs once. But that had been from the precivi-lized days of men, and the bombs had been dismantled and destroyed more than sixty years before.

It was in the hydroponics room that he was forced to face the truth. The plants there had been the means of replacing the oxygen in the air for the men, and now the tanks were dry and the vegetation had been dead so long that only desiccated stalks remained. There could be no men here. He didn't need the sight of the bare food section for confirmation. Some men had stayed here until the food was gone before they left the un-tended plants to die. It must have been many years ago that they had abandoned the station.

Sam shook his head in anger at himself. He should have guessed it when he saw that there were none of the winged rocket ships waiting outside the station.

So long as men were here, they would have kept some means for return to Earth.

The observatory was dark, but there was still power for the electronic telescope. The screen lighted at his touch, showing only empty s.p.a.ce. He had to wait nearly two hours before the slow tumble of the station brought Earth into full view.

Most of it was in daylight, and there was only a thin cloud cover. Once a thousand cities could have been scanned plainly from here. When seeing was best, even streams of moving cars could be seen. But now there were no cities and no signs of movement!

Sam emitted a harsh gasping sound as he scanned the continent of North America. He had seen pictures of New York, Chicago, and several other city complexes from this view. Now there was only dark ruin showing where they had been. It came to him with an almost physical shock that perhaps millions of human beings had died in those wrecks of cities.

There were still-smaller towns where he could make out the pattern of houses.

But there was no movement, even there.

He cut power from the telescope with an angry flick of his finger, trying to blot the things he had seen from his memory. He moved rapidly away from the observatory, hunting the communications section.

It was in worse shape than most other places. It looked as if some man had deliberately tried to wreck the machinery. A hammer lay tangled in a maze of rum that must once have been the main receiver. There was something that looked like dried blood on a metal cabinet, with a dent that might have fitted a human fist.

The floor was littered with tape that should have held a record of all the communications received and sent, and the drive capstan on the tape player was bent into uselessness. Sam lifted a section of tape and placed it in the slot that gave his face a sad caricature of a mouth. The tape sensors moved into place, and he began scanning the bit of plastic. It was blank, probably wiped of any message by time and the unshielded transformer that was still humming below the control panel.

Most of the tap cabinet was empty, and there was nothing on the ^evwlapes within. Sam ripped open drawers, hunting forUorrte evidence. He finally founda single reel in the top drawer of the main desk. Most of it was a garble of static; stray fields had gotten to it, even through the metal drawer. But towards the end, a few words could barely be picked out from the noise.

". . . shelters far enough from the blast . . . Thought we'd made it ... a starving . . . went mad. Must have been a nerve aerosol, but it didn't settle as . . . Mad. Everywhere. Southern hemisphere, too . . . For G.o.d's sake, stay where you . . ."

The noise grew worse then, totally ruining intelligibility. Sam caught bits of what might have been sentences, but they were pure gibberish. Then suddenly a small section of the tape near the hub became almost clear.

The voice was high-pitched now, and overmodulated, as if the words had been too loud to be carried by the transmitter. There was a strange, unpleasant quality that Sam had never heard in a human voice before.

". . . all shiny and bright. But it couldn't fool me. I knew it was one of them! They're all waiting up there, waiting for me to come out. They want to eat my soul. They're clever now, they won't let me see them. But when I turn my back, I can feel ..."

The tape Came to an end.

Sam could make no sense of it, though he replayed it all again in hopes of finding some other clue. He gave up and reached down to shut off the power in the transformer. It was amazing that the wreckage hadn't already blown all the fuses to this section. He groped for the switch and flipped it, just as his eyes spotted something under the transformer shelf.

It was a fountain pen, gold and black enamel. He had seen one like it countless times, and now as he turned it over in his hands, familiar lettering appeared on the barrel: RPS. Those were the initials of Dr. Smithers, and the pen could only have been his. He must have been one of those who had waited in the station. The Moon ships had made it back here, and Smithers had stayed on until the food was gone. Then he must have returned to Earth.

Sam reached out to clear the junk from the desk. He found paper in one of the drawers, and the pen still wrote as he sank into the chair.

There was metal sheet enough in the station, and tools to work it. The frame of the little taxi rocket he had seen outside would have to be modified; a nose and wings would have to be added, together with controls. Sam had studied the details of the upper stages of the rockets that went between the station and Earth, together with accounts of the men who flew the early ones. There had been enough books on all aspects of s.p.a.ce hi the dome.

He could never duplicate the winged craft accurately, nor could he be sure he could handle one down through the atmosphere. But in theory, almost any winged craft with a shallow angle of glide could be brought down slowly enough to avoid burning from the friction of the air. At least he was lucky enough to have fuel here; the emergency station tanks were half-filled with the mono- propellant suited for the little motor in the ferry.

Then he swore, using unprofane but colorful words he had learned from a score of historical novels. It would be at least another year before he could hope to complete his work on the craft.

5.

Surprisingly, the modified ferry behaved far better than Sam had dared to hope. It heated badly at the first touches of atmosphere, but the temperature remained within the limits he and the craft could stand. He learned slowly to control the descent to a glide neither too shallow for stability nor too steep to avoid overheating. By the time he was down to thirty miles above the surface, he was almost pleased with the way it handled.

He had set his course to reach the underground creche that had been his home at awakening and during the first three years of his education, before they sent him to the Moonlit was the only home he knew on Earth. 4"V " * *

Now he saw'ffiai he could never make it. The first fifteen minutes in the upper layers of atmosphere had been at too steep a glide angle, and he could never descend far inland. He might even have trouble reaching the sh.o.r.e at all, he realized; when the clouds thinned, he could see nothing but ocean under him.

He opened the rocket motor behind him gently, letting its thrust raise his speed to the highest his little craft could take at this alt.i.tude. But there was too little fuel left to help much. It might have given him an extra twenty miles of glide, but not more.

Sam considered the prospects of landing in the ocean with grim foreboding. He could exist in water for a while, even at fair depths. If he landed near the sh.o.r.e, he might work his way out. But within a limited period of tune, the water would penetrate through his body to some of the vital wiring. Once that was shorted, he would cease to exist.

He came down under the clouds, fighting for every inch of alt.i.tude. Then, far ahead, he could see the sh.o.r.e. There were no islands here, so it had to be the mainland. Once there, he could reach the creche in a single day.

He pa.s.sed over the sh.o.r.eline at a height of five hundred feet. There was a short stretch of sand, some woods, and then a long expanse of green that must be gra.s.s. He eased the control forward, then back again. The little ship came skimming down at two hundred miles an hour. Its skids touched the surface, and it bounded upward. Sam fought the controls to keep it from nosing over. Again it touched, jerking with deceleration. This time it seemed to have struck right. Then a hummock of ground caught against one skid. The craft slithered sideways and flipped over. Sam braced himself as the ship began coming to pieces around him. He pulled himself out, staring at the wreckage. It was a shame that it was ruined, he thought. But it couldn't be made as strong as he was and still glide through the air.

He turned to study the world around him. The gra.s.s was knee-high, moving gently in the wind. Beyond it lay woods. Sam had seen only pictures of trees like that before. He moved toward them, noticing the thickness of the underbrush around them. Below them, the dirt was dark and moist. He lifted a pinch to his face, moving his smell receptors forward in his mouth slit. It was a rich smell, richer than the stuff in the hydroponic tanks. He lifted his head to look for the birds he expected, but he could see no sign of them.

There were only insects, buzzing and humming.

The sun had already set, he noticed. Yet it was not yet dark. There was a paling of the light, and a soft diffusion. He shook his head. Above him, tiny twinkling spots began to appear. He had read that the stars twinkled, but he had thought it only fiction. He had never been under the open sky of Earth before.

Then a soft murmur of sound reached him. He started away, to be drawn back to it. Slowly he realized it was a sound like the description of that heard near the sea. He had never seen an ocean, either. And now one lay no more than a mile away.

He stumbled through the woods in the growing darkness. For some reason, he was reluctant to turn on his lights. Eventually, he learned to make his way through the brush and around the trees. The sound grew louder as he progressed.

It was dark when he reached the seash.o.r.e, but there was a hint of faint light to the east. As he watched, it increased. A pale white arc appeared over the horizon and grew to a large circle. The Moon, he realized finally.

The waves rose and fell, booming into surf. And far out across the sea, the Moon seemed to ride on the waves, casting a silver road of light over the water.

Sam had remembered a word. Now for the first tune, he found an understandingof it. This was Beauty.

He sighed as he heaved himself from the sand and began heading along the sh.o.r.e in search of a road that would take him westward. No wonder men wanted to come back to defend a world where something like this could be seen. ^ The Moon r0"se higher as he moved on, its light now bright enough to give him clear vision. He came over a small rise in the ground and spotted what seemed to be a road beyond it. Beside the road was a house. It was dark and quiet, but he swung aside, going through a copse of woods to reach it and search for any evidence of humanity.

The windows were mostly broken, he saw as he approached. And weeds had grown up around it. There was a detached building beside it that held a small car, by what he could see from the single dusty window. He skirted that and reached the door of the house; it opened at his touch, its hinges protesting rustily.

Inside, the moonlight shone through the broken windows on a jumble of furniture that was overturned and tossed about in no order Sam could see. And there were other things-white things that lay sprawled on the floor.

He recognized them from the pictures in the books- skeletons of human beings.

Two smaller skeletons were tangled in one corner with their skulls bashed in.

A large skeleton lay near them, with the rusty shape of a knife shoved through a sc.r.a.p of clothing between two ribs. There was a revolver near one hand.

Across the room, a skeleton in the tatters of a dress was a jumbled pile of bones, with a small hole in the skull that could have come from a bullet.

Sam backed out of the room. He knew the meaning of another word now. He had seen Madness.

Men had learned to build good machines. The car motor barely turned over after Sam had figured out the controls, but it caught and began running with only a slight sputtering. The tires were slightly soft, but they took the b.u.mps of the rutted little trail. Later, when Sam found a better road, they lasted under the punishment of high speed. Most of the road was clear. There were few vehicles along its way, and most of those seemed to have drifted to the shoulder before they stopped or crashed.

The sun was just rising when Sam located the place where the factory and warehouse had served as a legitimate cover for the secret underground robot project. Fire and weather had left only gutted ruins and rusty things that had once been machines. But the section that housed the creche entrance now stood apart from the rest, almost unharmed.

Sam moved into it and to the metal door openly concealed among other such doors. He should probably not have known the combination, but men were often careless around robots, and he had been curious enough to note and remember the details. He bent to what seemed to be an ornamental grille and called out a series of numbers.

The door seemed to stick a little, but then it moved aside. Beyond lay the elevator,- and that operated smoothly at the combination he punched. Power was still on, at least. There was no light, but the bulbs sprang into Life as he found a switch.

He called out once, but he no longer expected to find men so easily. The place had the feel of abandonment. And while it could have protected its workers from almost anything, there had been only enough food and water stocked here for two weeks. There were a few signs that it had been used for a shelter, but most of it was in good order.

He moved back past offices and laboratories toward the rear. The real creche, with its playrooms and learning devices, was empty, he saw. No robots had been receiving postawakening training. Sam was not surprised. He knew that most of the work here had been devoted to exploring the possibilities of robots, with the actual construction only a necessary sideline. Usually, the brain complexes had been created and tested without bodies, and then extinguished before there had been a full awakening.He started toward the educator computer out of his old habits. But it was only a machine that had programmed his progress from prepared tapes and memory circuits. It could not help him now.

Beyond the creche lay the heart of the whole affair.

Here the brain complexes were a.s.sembled from components according toJfesoteric calculations or to meet previously recordeU'&pecifications. This was work that required a computer that was itself intelligent to some extent. It had to make sense out of the desirable options given it by men and then form the brain paths needed, either during construction or during the initial period before awakening. Everything that Sam had been before awakening had come from this, with only the selection of his characteristics chosen by men. That pattern would still be recorded, along with what the great computer had learned of him during his previous return here.

Sam moved toward the machine, gazing in surprise at the amount of work lying about. There were boxes of robot bodies crammed into every storage s.p.a.ce. They could never have been a.s.sembled in such numbers here. And beyond lay shelves jammed with the components for the brain complexes. With such quant.i.ties, enough robots could be made to supply the Lunar Base needs for generations.

The computer itself was largely hidden far below, but its panel came to life at his touch. It waited.

"This is Robot Twelve, Mark One," Sam said. "You have authorization on file."

The authorization from Dr. DeMatre should have been canceled. But the machine did not switch on alarm circuits. A thin cable of filaments reached out and pa.s.sed into Sam's mouth slit. It retracted, and the speaker came to life.

"There is authorization. What is wanted?"

"What is the correct date?" Sam asked. Then he grunted as the answer came from the machine's isotope clock. It had been more than thirty-seven years since the men had left the Moon. He shook his head, and the robot bodies caught his attention again. "Why are so many robots being built?"

"Orders were received for one thousand robots trained to fly missiles. Orders were suspended by Director DeMatre. No orders were received for removing parts."

"Do you know what happened to the men?" Sam had little hope of finding an easy answer anymore, but he had to ask.

The machine seemed to hesitate. "Insufficient data. Orders were given by Director DeMatre to monitor broadcasts. Broadcasts were monitored. a.n.a.lysis is incomplete. Data of doubtful coherence. Requests, for more data were broadcast on all frequencies for six hours. Relevant replies were not received. Request further information if available."

"Never mind," Sam told it. "Can you teach me how to fly a plane?"

"Robot Twelve, Mark One, was awakened with established ability to control all vehicles. Further instructions not possible."

Sam grunted hi amazement. He'd been surprised at how well he had controlled the landing craft and then the car. But it had never occurred to him that such knowledge had been built in.

"All right," he decided. "Start broadcasting again on all the frequencies you can handle. Just ask for answers. If you get any, find where the sender is and record it. If anyone asks who is calling, say you're calling for me and take any message. Tell them I'll be back here in one month." He started to turn away, then remembered. "Finished for now."

The machine darkened. Sam headed out to find a field somewhere that might still have an operable plane. But he was already beginning to suspect what he would find on this travesty of Earth.