But perversely, now that the terminals lay before him, he hesitated. After all, the instructions had not mentioned the ratchet; it was too obvious to need mention, but ... He tried to picture such ignorance, staring at one of the elementary radio books above him, "Application of a Cavity Resonator."

Mentally, he could realize that a nonscience translation was meaningless : Use of a sound producer or strengthener in a hole! And then the overlooked factor struck him.

"But you did get out!"

"Because I lost my temper and threw the pickax. That's how I found the blade, not the handle, was metal. The only machines I could use were the projector and typer I was meant to use-and the typer broke!"

"Umm." He picked up the little machine, noting the yellowed incomplete page still hi it, even as he slipped the carriage tension cord back on its hook.

But his real attention was devoted to the cement dust ground into the splintered handle of the pick.

No man or robot could be such a complete and hope- less dope, and yet he no longer doubted. She was a robot moron! And if knowledge were evil, then surely she belonged to G.o.d! All the horror of his contemplated murder vanished, leaving his mind clean and weak before the relief that flooded him as he motioned her out.

"All right, you're not evil. You can go."

"And you?"

And himself? Before, as Satan, her arguments would have been plausible, and he had discounted them. But now-it had been the Tree of Knowledge of Good and Evil! And yet ...

"Dogs!" She caught at him, dragging him to the entrance where the baying sound was louder. "They're hunting you, Adam-^dozens of them!"

He nodded, studying the distant forms of men on horseback, while his fingers busied themselves with a pencil and sc.r.a.p of paper. "And they'll be here hi twenty minutes. Good or evil, they must not find what's here. Eve, there's a boat by the river; pull the red handle the way you want to go, hard for fast, a light pull for slow. Here's a map to my cave, and you'll be safe there."

Almost instantly, he was back at the excavator and in its saddle, his fingers flashing across its panel; its heavy generator bellowed gustily, and the squat, heavy machine began twisting through the narrow aisles and ramming obstructions aside. Once outside, where he could use its full force without danger of backwash, ten minutes would leave only a barren hill; and the generator could be overdriven by adjustment to melt itself and the machine into useless slag.

"Adam!" She was spraddling into the saddle behind him, shouting over the roar of the thin blade of energy that was enlarging the tunnel.

"Go on, get away, Eve! You can't stop me!"

"I don't want to-they're not ready for such machines as this, yet! And between us, we can rebuild everything here, anyhow. Adam?"He grunted uneasily, unable to turn away from the needle beam. It was hard enough trying to think without her distraction, knowing that he dared not take chances and must destroy himself, while her words and the instincts within him fought against his resolution. "You talk too much!"

"And I'll talk a lot more, until you behave sensibly! You'll make your mind sick, trying to decide now; come up the river for six months with me. You can't do any harm there, even if you are Satan! Then, when you've thought it over, Adam, you can do what you like. But not now!" '

"For the last time, will you go?" He dared not think now, while he was testing his way through the flawed, cracked cement, and yet he could not quiet his mind to her words that went on and on. "Go!"

"Not without you! Adam, my receiver isn't defective; I knew you'd try to kill me when I rescued you! Do you think I'll give up so easily now?"

He snapped the power to silence with a rude hand, flinging around to face her.

"You knew-and still saved me? Why?"

"Because I needed you, and the world needs you. You had to live, even if you killed me!"

Then the generator roared again, knifing its way through the last few inches, and he swung out of the dome and began turning it about. As the savage bellow of full power poured out of the main orifice, he turned his head to her and nodded.

She might be the dumbest robot in creation, but she was also the sweetest. It was wonderful to be needed and wanted!

And behind him, Eve nodded to herself, blessing Simon Ames for listing psychology as a humanity. In six months, she could complete his reeducation and still have time to recite the whole of the Book he knew as a s.n.a.t.c.h of film. But not yet! Most certainly not Leviticus yet; Genesis would give her trouble enough.

It was wonderful to be needed and wanted!

Spring had come again, and Adam sat under one of the budding trees, idly feeding one of the new crop of piglets as Eve's hands moved swiftly, finishing what were to be his clothes, carefully copied from those of Dan.

They were almost ready to go south and mingle with men in the task of leading the race back to its heritage. Already the yielding plastic he had synthesized and she had molded over them was a normal part of them, and the tiny magnetic muscles he had installed no longer needed thought to reveal their emotions in human expressions. He might have been only an uncommonly handsome man as he stood up and went over to her.

"Still hunting G.o.d?" she asked lightly, but there was no worry on her face.

The metaphysical binge was long since cured.

A thoughtful smile grew on his face as he began donning the clothes. "He is still where I found Him- Something inside us that needs no hunting. No, Eve, I was wishing the other robot had survived. Even though we found no trace of his dome where your records indicated, I still feel he should be with us."

"Perhaps he is, in spirit, since you insist robots have souls. Where's your faith, Adam?"

But there was no mockery inside her. Souls or not, Adam's G.o.d had been very good to them.

And far to the south, an aged figure limped over rubble to the face of a cliff. Under his hands, a cleverly concealed door swung open, and he pushed inward, closing and barring it behind him, and heading down the narrow tunnel to a rounded cavern at its end. It had been years since he had been there, but the place was still home to him as he creaked down onto a bench and began removing tattered, travel-stained clothes. Last of all, he pulled a mask and gray wig from his head, to* reveal the dented and worn body of the thirdrobot.

He sighed wearily as he glanced at the few tattered books and papers he had salvaged from the ruinous growth of stalagmites and stalact.i.tes within the chamber, and at the corroded switch the unplanned dampness had shorted seven hundred years before. And finally, his gaze rested on his greatest treasure.

It was faded, even under the plastic cover, but the bitter face of Simon Ames still gazed out in recognizable form.

The third robot nodded toward it with a strange mixture of old familiarity and ever-new awe. "Over two thousand miles in my condition, Simon Ames, to check on a story I heard in one of the colonies, and months of searching for them.

But I had to know. Well, they're good for the world. They'll bring all the things .1 couldn't, and their thoughts are young and strong, as the race is young and strong."

For a moment, he stared about the chamber and to the tunnel his adapted bacteria had eaten toward the outside world, resting again on the picture.

Then he cut off the main generator and settled down in the darkness.

"Seven hundred years since I came out to find man extinct on the earth," he told the picture. "Four hundred since I learned enough to dare attempt his recreation, and over three hundred since the last of my su-perfrozen human ova grew to success. Now I've done my part. Man has an unbroken tradition back to your race, with no knowledge of the break. He's strong and young and fruitful, and he has new leaders, better than I could ever be alone. I can do no more for him!"

For a moment there was only the sound of his hands sliding against metal, and then a faint sigh. "Into my hands, Simon Ames, you gave your race. Now, into Thy Hands, G.o.d of that race, if You exist as my brother believes, I commend him-and my spirit."

Then there was a click as his hands found the switch to his generator, and final silence.

And It Comes Out Here

No, YOU'RE WRONG. I'm not your father's ghost, even if I do look a bit like him. But it's a longish story, and you might as well let me in. You will, you know, so why quibble about it? At least, you always have ... or do ... or will. I don't know, words get all mixed up. We don't have the right att.i.tude toward tense for a situation like this.

Anyhow, you'll let me in. I did.

Thanks. You think you're crazy, of course, but you'll find out you aren't.

It's just that things are a bit confused. And don't look at the machine out there too long-until you get used to it, you'll find it's hard on the eyes, trying to follow where the vanes go. You'll get used to it, of course, but it will take about thirty years.

You're wondering whether to give me a drink, as I remember it. Why not? And naturally, since we have the same tastes, you can make the same for me as you're having. Of course we have the same tastes- we're the same person. I'm you thirty years from now- or you're me. I remember just how you feel-I felt the same way when he came back to tell me about it, thirty years ago.

Here, have one of these cigarettes. You'll get to like them in a couple more years. And you can look at the revenue stamp date, if you still doubt my story. You'll believe it eventually, though, so it doesn't matter. .- Right now, you're shocked-it's a bit rugged when a man meets himself for the first time. Some kind of telepathy seems to work between two of the same people-you sense things. So I'll simply go ahead talking for half an hour or so, until you get over it. After that, you'll come along with me. You know, I could try to change things around by telling what happened to me; but he told me what I was going to do, so I might as well do the same. I probably couldn't help telling you the same thing in the same words, even if I tried-and I don'tintend to try. I've gotten past that stage in worrying about things.

So let's begin when you get up in half an hour and come out with me. You'll take a closer look at the machine, then. Yeah, it'll be pretty obvious it must be a time machine-you'll sense that, too. You've seen it- just a small little cage with two seats, a luggage compartment, and a few b.u.t.tons on a dash.

You'll be puzzling over what I'll fell you, and you'll be getting used to the idea that you are the guy who makes atomic power practical. Jerome Boell, just plain engineer, the man who put atomic power in every home. You won't exactly believe it, but you'll want to go along.

I'll be tired of talking by then, and in a hurry to get going. So I cut off your questions, and get you inside. I snap on a green b.u.t.ton, and everything seems to cut off around us-you can see a sort of foggy nothing surrounding the c.o.c.kpit; it is probably the field that prevents pa.s.sage through time from affecting us. The luggage section isn't protected, though.

You start to say something, but by then I'm pressing a black b.u.t.ton, and everything outside will disappear. You look for your house, but it isn't there. There is exactly nothing there-in fact, there is no there. You are completely outside of time and s.p.a.ce, as best you can guess how things are.

You can't feel any motion, of course. You try to reach a hand out through the field into the nothing around you-and your hand goes out, all right, but nothing happens. Where the screen ends, your hand just turns over and pokes back at you. Doesn't hurt, and when you pull your arm back, you're still sound and uninjured. But it looks odd, and you don't try it again.

Then it comes to you slowly that you're actually traveling in time. You turn to me, getting used to the idea. "So this is the fourth dimension?"

Then you feel silly, because you'll remember that I said you'd ask that. Well, I asked it after I was told, then I came back and told it to you, and I still can't help answering when you speak.

"Not exactly," I try to explain. "Maybe it's no dimension-or it might be the fifth; if you're going to skip over the so-called fourth without traveling along it, you'd need a fifth. Don't ask me. I didn't invent the machine, and I don't understand it."

"But . . ."

I let it go, apd so do you. That's a good way of going crazy. You'll see why I couldn't have invented the machine later. Of course, there may have been a start for all this once. There may have been a time when you did invent the machine-the atomic motor first, then the time machine. And when you closed the loop by going back and saving yourself the trouble, it got all tangled up. I figured out once that such a universe would need some seven or eight time and s.p.a.ce dimensions. It's simpler just to figure that this is the way time got kinked on itself. Maybe there is no machine, and it's just easier for us to imagine it. When you spend thirty years thinking about it, as I did-and you will-you get further and further from an answer.

Anyhow, you sit there, watching nothing all around you-and no time, apparently, though there is a time effect back in the luggage s.p.a.ce. You look at your watch, and it's still running. That means you either carry a small time field with you, or you are catching a small increment of time from the main field. I don't know, and you won't think about that then, either.

I'm smoking, and so are you, and the air in the machine is getting a bit stale. You suddenly realize that everything in the machine was wide open, yet you haven't seen any effects of air loss.

"Where are we getting our air?" you ask. "Or why don't we lose it?"

"No place for it to go," I explain. There isn't-out there is neither time nor s.p.a.ce, apparently. How could the air leak out? You still feel gravity, but I can't explain that, either. Maybe the machine has a gravity field built in-or maybe the time that makes your watch run is responsible for gravity. In spiteof Einstein, you have always had the idea that time is an effect of gravity, and I sort of agree, still.

Then the machine stops-at least, the field around us cuts off. You feel a dankish sort of air replace the stale air, and you breathe easier, though we're in complete darkness, except for the weak light in the machine, which always burns, and a few feet of rough dirty cement floor around. You take another cigarette from me and you get out of the machine, just as I do.

I've got a bundle of clothes, and I start changing. It's a sort of simple, short-limbed, one-piece affair I put on, but it looks comfortable.

"I'm staying here," I tell you. "This is like the things they wear in this century, as near as I can remember it, and I should be able to pa.s.s fairly well. I've had all my fortune-the one you make on that atomic generator- invested in such a way I can get it on using some identification I've got with me, so I'll do all right. I know they still use some kind of money-you'll see evidence of that. And it's a pretty easy-going civilization, from what I could see. We'll go up, and I'll leave you. I like the looks of things here, and I won't be coming back with you."

You nod, remembering I've told you about it. "What century is this, anyway?"

I'd told you that, too, but you've forgotten. "As near as I can guess, it's about 2150. He told me, just as I'm telling you, that it's an interstellar civilization."

You take another cigarette from me, and follow me. Fve ^ot a small flashlight, and we grope through a pile of rubbish, and out into a corridor. This is a sub-sub-subbas.e.m.e.nt. We have to walk up a flight of stairs, and there is an elevator waiting, fortunately with the door open. c "What about the time machine?" you ask.

"Since n.o.body ever stole it, it's safe."

We get in the elevator, and I say "first" to it. It gives out a coughing noise, and the bas.e.m.e.nt openings begin to click by us. There's no feeling of acceleration-some kind of false gravity they use in the future. Then the door opens, and the elevator says "first" back at us.

It's obviously a service elevator, and we're in a dim corridor, with n.o.body around. I grab your hand and shake it. "You go that way. Don't worry about getting lost; you never did, so you can't. Find the museum, grab the motor, and get out. And good luck to you."

You act as if you're dreaming, though you can't believe it's a dream. You nod at me, and I move out into the main corridor. A second later, you see me going by, mixed into a crowd that is loafing along toward a restaurant, or something like it, that is just opening. I'm asking questions of a man, who points, and I turn and move off.

You come out of the side corridor, and go down a hall, away from the restaurant. There are quiet little signs along the hall. You look at them, realizing that things have changed.

STEIJ:NERI, FAUNTEN, Z:RGOT DISPENSERI. The signs are very quiet and dignified. Some of them can be decoded to stationery shops, fountains, and the like. What a zergot is, you don't know. You stop at a sign that announces: TRAV:L BIWROU-F:RST-CLAS TWRZ- MARZ AND X: TROUDJ:N PLANETS. SPEJ:L REITS TU AOL.

S:NZ WTXIN 60 LYT IIRZ! But there is only a single picture of a dull-looking metal sphere, with pa.s.sengers moving up a ramp, and the office is closed. You begin to get the hang of the spelling they use, though.

Now there are people around you, but n.o.body pays much attention to you. Why should they? You wouldn't care if you saw a man in a leopard-skin suit-you'd figure it was some part in a play, and let it go. Well, people don't change much.

You get up your courage and go up to a boy sellingsomething that might be papers on tapes. "Where can I find the Museum of Science?"

Downayer rien turn lefa the sign. Stoo bloss," he tells you. Around you, you hear some pretty normal English, but there are others using stuff as garbled as his. You go right until you find a big sign built into the rubbery surface of the walk: MIUZI:M :v SYENS. There's an arrow pointing, and you turn left.

Ahead of you, two blocks 'on, you can see a pink building, with faint aqua tr.i.m.m.i.n.g, bigger than most of the others. They are building lower than they used to, apparently. Twenty floors up seems about the maximum. You head for it, and find the sidewalk is marked with the information that it is the museum.

You go up the steps, but you see that it seems to be closed. You hesitate for a moment, then. You're beginning to think the whole affair is a bunch of nonsense, and you should get back to the tune machine and go home. But then a guard comes to the gate-except for the short legs in his suit, and the grin on his face, he looks like any other guard.

What's more, he speaks pretty clearly. Everyone says things in a sort of drawl, with softer vowels, and slurred consonants, but it's rather pleasant.

"Help you, sir? Oh, of course. You must be playing in 'Atoms and Axioms.' The museum's closed, but I'll be glad to let you study whatever you need for color in your role. Nice show. I saw it twice."

"Thanks," you mutter, wondering what kind of a civilization can produce guards as polite as that. "I-I'm told I should investigate your display of atomic generators."

He beams at that. "Of course." The gate is swung to behind you, but obviously he isn't locking it-in fact, there doesn't seem to be a lock. "Must be a new part. You go down that corridor, up one flight of stairs, and left. Finest display in the worlds. We've got the original of the first thirteen models.

Profesor Jonas was using them to check his latest theory of how they work. Too bad he couldn't explain the principle, either. Someone will, some day, though.

Lord, the genius of that twen- tieth century inventor! It's quite a hobby with me, sir. I've read everything I could get on the period. Oh- congratulations on your p.r.o.nunciation. Sounds just like some of our oldest tapes."

You get away from him, finally, after some polite thanks. The building seems deserted, and you wander up the stairs. There's a room on your right filled with something that proclaims itself the first truly plastic diamond former, and you go up to it. As you come near, it goes through a crazy wiggle inside, stops turning out a continual row of what seem to be bearings, and slips a hunk of something about the size of a penny toward you. "Souvenir," it announces in a well-modulated voice. "This is a typical gemstone of the twentieth century, properly cut to fifty-eight facets, known technically as a Jaegger diamond, and approximately twenty carats in size. You can have it made into a ring on the third floor during morning hours for one-tenth credit. If you have more than one child, press the red b.u.t.ton for the number of stones you desire."

You put it in your pocket, gulping a little, and get back to the corridor. You turn left, and go past a big room in which models of s.p.a.ce ships-from the original thing that looks like a V-2, and is labeled first lunar rocket, to a ten-foot globe, complete with miniature manikins-are sailing about in some kind of orbits. Then there is one labeled WEP:NZ, filled with everything from a crossbow to a tiny little rod four niches long and half the size of a pencil, marked FYN:L HAND-ARM. Beyond is the end of the corridor, and a big place that bears a sign, MOD:LZ :v ATOMIC PAU:R SORSEZ.

By that tune, you're almost convinced. And you've been doing a lot of thinking about what you can do. The story I'm telling has been sinking in, but you aren't completely willing to accept it.You notice that the models are all mounted on tables, and that they're a lot smaller than you thought. They seem to be in chronological order, and the latest one, marked 2147-RINGS DYN:POT, is about the size of a desk telephone.

The earlier ones are larger, of course, but with variations, probably depending on the power output. A big sign on the ceiling gives a lot of dope on atomic generators, explaining that this is the first invention which sprang full blown into basically final form.

You study it, but it mentions casually the inventor, without giving his name- either they don't know it, or they take it for granted that everyone does, which seems more probable. They call attention to the fact that they have the original model of the first atomic generator built, complete with design drawings, original ma.n.u.script on operation, and full patent application. They state that it has all major refinements, operating on any fuel, producing electricity at any desired voltage up to five million, any chosen cyclic rate from direct current to one thousand megacycles, and any amperage up to one thousand, its maximum power output being fifty kilowatts, limited by the current-carrying capacity of the outputs. They also mention that the operating principle is still being investigated, and that only such refinements as better alloys and the addition of magnetric and nucleatric current outlets have been added since the original.

So you go to the end and look over the thing. It's simply a square box with a huge plug on each side, and a set of vernier controls on top, plus a little hole marked in old-style spelling, DROP BB'S OR WIRE HERE. Apparently that's the way it's fueled. It's about one foot on a side.

"Nice," the guard says over your shoulder. "It finally wore out one of the cathogrids, and we had to replace that, but otherwise it's exactly as the great inventor made it. And it still operates as well as ever. Like to have me tell you about it?"

"Not particularly," you begin, and then realize bad manners seem to be out up here. While you're searching for an answer, the guard pulls something out of his pocket and stares at it.

"Fine, fine. The mayor of Altasecarba-Centaurian, you know-is arriving, but I'll be back in about ten minutes. He wants to examine some of the weapons for a monograph on Centaurian primitives compared to nineteenth-century man.

You'll pardpn me?"