"I was thinking of Terra. Here," Mary said. "Reconstruct work on it will take generations; all the talent and ability you reconstruct engineers possess will be required." She added, "I'm just following your hypothetical logic, of course."

"So Terra's our next job. That's why you let me come here. In fact I'm going tostay here." He realized that, thoroughly and utterly, in a flash of insight. "I won't be going back to Mars and I won't see Fay again. You're replacing her." It all made sense.

"Well," Mary said, with a faint wry smile, "let's say I'm attempting to." She stroked his arm.

Barefoot, still in her sunsuit, she moved slowly closer and closer to him.

Frightened, he backed away from her. Picking up the dead wug-plant he numbly carried it to the apt's disposal chute and dropped the brittle, dry remains in. They vanished at once.

"And now," Mary said busily, "we're going to visit the Museum of Modern Art in New York and then, if we have time, the Smithsonian in Washington, D.C. They've asked me to keep you busy so you don't start brooding."

"But I am brooding," Milt said as he watched her change from her sunsuit to a gray wool knit dress. Nothing can stop that, he said to himself. And you know it now. And as each reconstruct engineer finishes his area it's going to happen again. I'm just the first.

At least I'm not alone, he realized. And felt somewhat better.

"How do I look?" Mary asked as she put on lipstick before the bedroom mirror.

"Fine," he said listlessly, and wondered if Mary would meet each reconstruct engineer in turn, become the mistress of each. Not only is she not what she seems, he thought, but I don't even get to keep her.

It seemed a gratuitous loss, easily avoided.

He was, he realized, beginning to like her.Mary was alive ; that much was real. Terran or not. At least they had not lost the war to shadows; they had lost to authentic living organisms. He felt somewhat cheered.

"Ready for the Museum of Modern Art?" Mary said briskly, with a smile.

Later, at the Smithsonian, after he had viewed the Spirit of St. Louis and the Wright brothers'

incredibly ancient plane -- it appeared to be at least a million years old -- he caught sight of an exhibit which he had been anticipating.

Saying nothing to Mary -- she was absorbed in studying a case of semiprecious stones in their natural uncut state -- he slipped off and, a moment later, stood before a glass-walled section entitled

PROX MILITARY OF 2014.

Three Prox soldiers stood frozen, their dark muzzles stained and grimy, side arms ready, in a makeshift shelter composed of the remains of one of their transports. A bloody Prox flag hung drably.

This was a defeated enclave of the enemy; these three creatures were about to surrender or be killed.

A group of Terran visitors stood before the exhibit, gawking. Milt Biskle said to the man nearest him, "Convincing, isn't it?"

"Sure is," the man, middle-aged, with glasses and gray hair, agreed. "Were you in the war?" he asked Milt, glancing at him.

"I'm in reconstruct," Milt said. "Yellow Engineer."

"Oh." The man nodded, impressed. "Boy, these Proxmen look scary. You'd almost expect them to step out of that exhibit and fight us to the death." He grinned. "They put up a good fight before they gave in, those Proxmen; you have to give 'em credit for that."

Beside him the man's gray, taut wife said, "Those guns of theirs make me shiver. It's too realistic."

Disapproving, she walked on.

"You're right," Milt Biskle said. "They do look frighteningly real, because of course they are."

There was no point in creating an illusion of this sort because the genuine thing lay immediately at hand, readily available. Milt swung himself under the guard rail, reached the transparent glass of the exhibit, raised his foot and smashed the glass; it burst and rained down with a furious racket of shivering fragments.

As Mary came running, Milt snatched a rifle from one of the frozen Proxmen in the exhibit and turned it toward her.

She halted, breathing rapidly, eyeing him but saying nothing.

"I am willing to work for you," Milt said to her, holding the rifle expertly. "After all, if my own race no longer exists I can hardly reconstruct a colony world for them; even I can see that. But I want to know the truth. Show it to me and I'll go on with my job."

Mary said, "No, Milt, if you knew the truth you wouldn't go on. You'd turn that gun on yourself."

She sounded calm, even compassionate, but her eyes were bright and enlarged, wary.

"Then I'll kill you," he said. And, after that, himself.

"Wait." She pondered. "Milt -- this is difficult. You know absolutely nothing and yet look how miserable you are. How do you expect to feel when you can see your planet as it is? It's almost too much for me and I'm --" She hesitated.

"Say it."

"I'm just a --" she choked out the word -- "a visitor."

"But I am right," he said. "Say it. Admit it."

"You're right, Milt," she sighed.

Two uniformed museum guards appeared, holding pistols. "You okay, Miss Ableseth?"

"For the present," Mary said. She did not take her eyes off Milt and the rifle which he held. "Just wait," she instructed the guards.

"Yes ma'am." The guards waited. No one moved.

Milt said, "Did any Terran women survive?"

After a pause, Mary said, "No, Milt. But we Proxmen are within the same genus, as you well know. We can interbreed. Doesn't that make you feel better?"

"Sure," he said. "A lot better." And he did feel like turning the rifle on himself now, without waiting. It was all he could do to resist the impulse. So he had been right; that thing had not been Fay, there at Field Three on Mars. "Listen," he said to Mary Ableseth, "I want to go back to Mars again. I came here to learn something. I learned it, now I want to go back. Maybe I'll talk to Dr. DeWinter again, maybe he can help me. Any objection to that?"

"No." She seemed to understand how he felt. "After all, you did all your work there. You have a right to return. But eventually you have to begin here on Terra. We can wait a year or so, perhaps even two. But eventually Mars will be filled up and we'll need the room. And it's going to be so much harder here. . . as you'll discover." She tried to smile but failed; he saw the effort. "I'm sorry, Milt."

"So am I," Milt Biskle said. "Hell, I was sorry when that wug-plant died. I knew the truth then. It wasn't just a guess."

"You'll be interested to know that your fellow reconstruct engineer Red, Cleveland Andre, addressed the meeting in your place. And passed your intimations on to them all, along with his own.

They voted to send an official delegate here to Terra to investigate; he's on his way now."

"I'm interested," Milt said. "But it doesn't really matter. It hardly changes things." He put down the rifle. "Can I go back to Mars now?" He felt tired. "Tell Dr. DeWinter I'm coming." Tell him, he thought, to have every psychiatric technique in his repertory ready for me, because it will take a lot. "What about Earth's animals?" he asked. "Did any forms at all survive? How about the dog and the cat?"

Mary glanced at the museum guards; a flicker of communication passed silently between them and then Mary said, "Maybe it's all right after all."

"What's all right?" Milt Biskle said.

"For you to see. Just for a moment. You seem to be standing up to it better than we had expected. In our opinion youare entitled to that." She added, "Yes, Milt, the dog and cat survived; they live here among the ruins. Come along and look."

He followed after her, thinking to himself, Wasn't she right the first time? Do I really want to look? Can I stand up to what exists in actuality -- what they've felt the need of keeping from me up until now?

At the exit ramp of the museum Mary halted and said, "Go on outside, Milt. I'll stay here. I'll be waiting for you when you come back in."

Haltingly, he descended the ramp.

And saw.

It was, of course, as she had said, ruins. The city had been decapitated, leveled three feet above ground-level; the buildings had become hollow squares, without contents, like some infinite arrangements of useless, ancient courtyards. He could not believe that what he saw wasnew ; it seemed to him as if these abandoned remnants had always been there, exactly as they were now. And -- how long would they remain this way?

To the right an elaborate but small-scale mechanical system had plopped itself down to a debris-filled street. As he watched, it extended a host of pseudopodia which burrowed inquisitively into the nearby foundations. The foundations, steel and cement, were abruptly pulverized; the bare ground, exposed, lay naked and dark brown, seared over from the atomic heat generated by the repair autonomic rig -- a construct, Milt Biskle thought, not much different from those I employ on Mars. At least to some meager extent the rig had the task of clearing away the old. He knew from his own reconstruct work on Mars that it would be followed, probably within minutes, by an equally elaborate mechanism which would lay the groundwork for the new structures to come.

And, standing off to one side in the otherwise deserted street, watching this limited clearing-work in progress, two gray, thin figures could be made out. Two hawk-nosed Proxmen with their pale, natural hair arranged in high coils, their earlobes elongated with heavy weights.

The victors, he thought to himself. Experiencing the satisfaction of this spectacle, witnessing the last artifacts of the defeated race being obliterated. Some day a purely Prox city will rise up here: Prox architecture, streets of the odd, wide Prox pattern, the uniform box-like buildings with their many subsurface levels. And citizens such as these will be treading the ramps, accepting the high-speed runnels in their daily routines. And what, he thought, about the Terran dogs and cats which now inhabit these ruins, as Mary said? Will even they disappear? Probably not entirely. There will be room for them, perhaps in museums and zoos, as oddities to be gaped at. Survivals of an ecology which no longer obtained. Or even mattered.

And yet -- Mary was right. The Proxmen were within the same genus. Even if they did not interbreed with the remaining Terrans the species as he had known it would go on. And they would interbreed, he thought. His own relationship with Mary was a harbinger. As individuals they were not so far apart. The results might even be good.

The results, he thought as he turned away and started back into the museum, may be a race not quite Prox and not quite Terran; something that is genuinely new may come from the melding. At least we can hope so.

Terra would be rebuilt. He had seen slight but real work in progress with his own eyes. Perhaps the Proxmen lacked the skill that he and his fellow reconstruct engineers possessed. . . but now that Mars was virtually done they could begin here. It was not absolutely hopeless. Notquite.

Walking up to Mary he said hoarsely, "Do me a favor. Get me a cat I can take back to Mars with me. I've always liked cats. Especially the orange ones with stripes."

One of the museum guards, after a glance at his companion, said, "We can arrange that, Mr.

Biskle. We can get a -- cub, is that the word?"

"Kitten, I think," Mary corrected.

On the trip back to Mars, Milt Biskle sat with the box containing the orange kitten on his lap, working out his plans. In fifteen minutes the ship would land on Mars and Dr. DeWinter -- or the thing that posed as Dr. DeWinter anyhow -- would be waiting to meet him. And it would be too late. From where he sat he could see the emergency escape hatch with its red warning light. His plans had become focussed around the hatch. It was not ideal but it would serve.

In the box the orange kitten reached up a paw and batted at Milt's hand. He felt the sharp, tiny claws rake across his hand and he absently disengaged his flesh, retreating from the probing reach of the animal. You wouldn't have liked Mars anyhow, he thought, and rose to his feet.

Carrying the box he strode swiftly toward the emergency hatch. Before the stewardess could reach him he had thrown open the hatch. He stepped forward and the hatch locked behind him. For an instant he was within the cramped unit, and then he began to twist open the heavy outer door.

"Mr. Biskle!" the stewardess's voice came, muffled by the door behind him. He heard her fumbling to reach him, opening the door and groping to catch hold of him.

As he twisted open the outer door the kitten within the box under his arm snarled.

You, too? Milt Biskle thought, and paused.

Death, the emptiness and utter lack of warmth of 'tween space, seeped around him, filtering past the partly opened outer door. He smelled it and something within him, as in the kitten, retreated by instinct. He paused, holding the box, not trying to push the outer door any farther open, and in that moment the stewardess grabbed him.

"Mr. Biskle," she said with a half-sob, "are you out of your mind? Good God, what are you doing?" She managed to tug the outer door shut, screw the emergency section back into shut position.

"You know exactly what I'm doing," Milt Biskle said as he allowed her to propel him back into the ship and to his seat. And don't think you stopped me, he said to himself. Because it wasn't you. I could have gone ahead and done it. But I decided not to.

He wondered why.

Later, at Field Three on Mars, Dr. DeWinter met him as he had expected.

The two of them walked to the parked 'copter and DeWinter in a worried tone of voice said, "I've just been informed that during the trip --"

"That's right. I attempted suicide. But I changed my mind. Maybe you know why. You're the psychologist, the authority as to what goes on inside us." He entered the 'copter, being careful not to bang the box containing the Terran kitten.

"You're going to go ahead and stake your landparcel with Fay?" Dr. DeWinter asked presently as the 'copter flew above green, wet fields of high protein wheat. "Even though -- you know?"

"Yes." He nodded. After all, there was nothing else for him, as far as he could make out.

"You Terrans." DeWinter shook his head. "Admirable." Now he noticed the box on Milt Biskle's lap. "What's that you have there? A creature from Terra?" He eyed it suspiciously; obviously to him it was a manifestation of an alien form of life. "A rather peculiar-looking organism."

"It's going to keep me company," Milt Biskle said. "While I go on with my work, either building up my private parcel or --" Or helping you Proxmen with Terra, he thought.

"Is that what was called a 'rattlesnake'? I detect the sound of its rattles." Dr. DeWinter edged away.

"It's purring." Milt Biskle stroked the kitten as the autonomic circuit of the 'copter guided it across the dully red Martian sky. Contact with the one familiar life-form, he realized, will keep me sane. It will make it possible for me to go on. He felt grateful. My race may have been defeated and destroyed, but not all Terran creatures have perished. When we reconstruct Terra maybe we can induce the authorities to allow us to set up game preserves. We'll make that part of our task, he told himself, and again he patted the kitten. At least we can hope for that much.

Next to him, Dr. DeWinter was also deep in thought. He appreciated the intricate workmanship, by engineers stationed on the third planet, which had gone into the simulacrum resting in the box on Milt Biskle's lap. The technical achievement was impressive, even to him, and he saw clearly -- as Milt Biskle of course did not. This artifact, accepted by the Terran as an authentic organism from his familiar past, would provide a pivot by which the man would hang onto his psychic balance.

But what about the other reconstruct engineers? What would carry each of them through and past the moment of discovery as each completed his work and had to -- whether he liked it or not -- awake?

It would vary from Terran to Terran. A dog for one, a more elaborate simulacrum, possibly that of a nubile human female, for another. In any case each would be provided with an "exception" to the true state. One essential surviving entity, selected out of what had in fact totally vanished. Research into the past of each engineer would provide the clue, as it had in Biskle's instance; the cat-simulacrum had been finished weeks before his abrupt, panic-stricken trip home to Terra. For instance, in Andre's case a parrot-simulacrum was already under construction. It would be done by the time he madehis trip home.

"I call him Thunder," Milt Biskle explained.

"Good name," Dr. DeWinter -- as he titled himself these days -- said. And thought, A shame we could not have shown him the real situation of Terra. Actually it's quite interesting that he accepted what he saw, because on some level he must realize that nothing survives a war of the kind we conducted.

Obviously he desperately wanted to believe that a remnant, even though no more than rubble, endures.

But it's typical of the Terran mind to fasten onto phantoms. That might help explain their defeat in the conflict; they were simply not realists.

"This cat," Milt Biskle said, "is going to be a mighty hunter of Martian sneak-mice."

"Right," Dr. DeWinter agreed, and thought,As long as its batteries don't run down. He, too, patted the kitten.

A switch closed and the kitten purred louder.