Then there followed Dmitri's visit to the ruins of Old New York, which he enjoyed with artless excitement (but then there was no more magnificent spectacle of the useless gigantism of the pre-Cats than Old New York).William began to wonder if the trip might not give him an opportunity to see some sights as well.

He even began to think that for some time he had been considering the possibility of finding a new bedmate, and it would be more convenient to find one in another geographical area where he would not stay permanently.

--Or was it that even then, when he knew nothing but the barest beginning of what was needed, there had already come to him, like the twinkle of a distant lightning flash, what might be done So he eventually went to Dallas and stepped out on the roof and there was Dmitri again, beaming. Then, with eyes narrowing, the little man turned and said, "I knew-- knew--What a remarkable resemblance!"

William's eyes opened wide and there, visibly shrinking backward, was enough of his own face to make him certain at once that Anthony was standing before him.

He read very plainly in Anthony's face a longing to bury the relationship. All William needed to say was "How remarkable!" and let it go. The gene patterns of mankind were complex enough, after all, to allow resemblances of any reasonable degree even without kinship.

But of course William was a h.o.m.ologist and no one can work with the intricacies of the human brain without growing insensitive as to its details, so he said, "I'm sure this is Anthony, my brother."

Dmitri said, "Your brother?"

"My father," said William, "had two boys by the same woman--my mother. They were eccentric people."

He then stepped forward, hand outstretched, and Anthony had no choice but to take it....The incident was the topic of conversation, the only topic, for the next several days.

It was small consolation to Anthony that William was contrite enough when he realized what he had done.

They sat together after dinner that night and William said, "My apologies. I thought that if we got the worst out at once that would end it. It doesn't seem to have done so. I've signed no papers, made no formal agreement. I will leave."

"What good would that do?" said Anthony ungraciously. "Everyone knows now. Two bodies and one face. It's enough to make one puke."

"If I leave--"

"You can't leave. This whole thing is my idea."

"To get me here?" William's heavy lids lifted as far as they might and his eyebrows climbed.

"No, of course not. To get a h.o.m.ologist h.o.m.ologist here. How could I possibly know they would send here. How could I possibly know they would send you?" you?"

"But if I leave--"

"No. The only thing we can do now is to lick the problem, if it can be done. Then--it won't matter." (Everything is forgiven those who succeed, he thought.) "I don't know that I can--"

"We'll have to try. Dmitri will place it on us. It's too good a chance. You two are brothers," Anthony said, mimicking Dmitri's tenor voice, "and understand each other. Why not work together?" Then, in his own voice, angrily, "So we must. To begin with, what is it you do, William? I mean, more precisely than the word 'h.o.m.ology' can explain by itself."

William sighed. "Well, please accept my regrets....I work with autistic children."

"I'm afraid I don't know what that means."

"Without going into a long song and dance, I deal with children who do not reach out into the world, do not communicate with others, but who sink into themselves and exist behind a wall of skin, somewhat unreachably. I hope to be able to cure it someday."

"Is that why you call yourself Anti-Aut?"

"Yes, as a matter of fact."

Anthony laughed briefly, but he was not really amused.

A chill crept into William's manner. "It is an honest name."

"I'm sure it is," muttered Anthony hurriedly, and could bring himself to no more specific apology. With an effort, he restored the subject, " And are you making any progress?"

"Toward the cure? No, so far. Toward understanding, yes. And the more I understand--" William's voice grew warmer as he spoke and his eyes more distant. Anthony recognized it for what it was, the pleasure of speaking of what fills one's heart and mind to the exclusion of almost everything else. He felt it in himself often enough.

He listened as closely as he might to something he didn't really understand, for it was necessary to do so. He would expect William to listen to him.

How clearly he remembered it. He thought at the time he would not, but at the time, of course, he was not aware of what was happening. Thinking back, in the glare of hindsight, he found himself remembering whole sentences, virtually word for word.

"So it seemed to us," William said, "that the autistic child was not failing to receive the impressions, or even failing to interpret them in quite a sophisticated manner. He was, rather, disapproving them and rejecting them, without any loss of the potentiality of full communication if some impression could be found which he approved of."

"Ah," said Anthony, making just enough of a sound to indicate that he was listening.

"Nor can you persuade him out of his autism in any ordinary way, for he disapproves of you you just as much as he disapproves of the rest of the world. But if you place him in conscious arrest--" just as much as he disapproves of the rest of the world. But if you place him in conscious arrest--"

"In what?"

"It is a technique we have in which, in effect, the brain is divorced from the body and can perform its functions without reference to the body. It is a rather sophisticated technique devised in our own laboratory; actually--" He paused.

"By yourself?" asked Anthony gently. "Actually, yes," said William, reddening slightly, but clearly pleased. "In conscious arrest, we can supply the body with designed fantasies and observe the brain under differential electroencephalography. We can at once learn more about the autistic individual; what kind of sense impressions he most wants; and we learn more about the brain generally."

"Ah," said Anthony, and this time it was a real ah. "And all this you have learned about brains-- can you not adapt it to the workings of a computer?"

"No," said William. "Not a chance. I told that to Dmitri. I know nothing about computers and not enough about brains."

"If I teach you about computers and tell you in detail what we need, what then?"

"It won't do. It--"

"Brother," Anthony said, and he tried to make it an impressive word. "You owe me something. Please make an honest attempt to give our problem some thought. Whatever you know about the brain--please adapt it to our computers."

William shifted uneasily, and said, "I understand your position. I will try. I will honestly try."

William had had tried, and as Anthony had predicted, the two had been left to work together. At first they encountered others now and then and William had tried to use the shock value of the announcement that they were brothers since there was no use in denial. Eventually that stopped, however, and there came to be a purposeful non-interference. When William approached Anthony, or Anthony approached William, anyone else who might be present faded silently into the walls. tried, and as Anthony had predicted, the two had been left to work together. At first they encountered others now and then and William had tried to use the shock value of the announcement that they were brothers since there was no use in denial. Eventually that stopped, however, and there came to be a purposeful non-interference. When William approached Anthony, or Anthony approached William, anyone else who might be present faded silently into the walls.

They even grew used to each other after a fashion and sometimes spoke to each other almost as though there were no resemblance between them at all and no childish memories in common.

Anthony made the computer requirements plain in reasonably non-technical language and William, after long thought, explained how it seemed to him a computer might do the work, more or less, of a brain.

Anthony said, "Would that be possible?"

"I don't know," said William. "I am not eager to try. It may not work. But it may."

"We' d have to talk to Dmitri Large."

"Let's talk it over ourselves first and see what we've got. We can go to him with as reasonable a proposition as we can put together. Or else, not go to him."

Anthony hesitated, "We both both go to him?" William said delicately, "You be my spokesman. There is no reason that we need be seen together." go to him?" William said delicately, "You be my spokesman. There is no reason that we need be seen together."

"Thank you, William. If anything comes of this, you will get full credit from me."

William said, "I have no worries about that. If there is anything to this, I will be the only one who can make it work, I suppose."

They thrashed it out through four or five meetings and if Anthony hadn't been kin and if there hadn't been that sticky, emotional situation between them, William would have been uncomplicatedly proud of the younger-brother--for his quick understanding of an alien field.

There were then long conferences with Dmitri Large. There were, in fact, conferences with everyone. Anthony saw them through endless days, and then they came to see William separately. And eventually, through an agonizing pregnancy, what came to be called the Mercury Computer was authorized.

William then returned to New York with some relief. He did not plan to stay in New York (would he have thought that possible two months earlier?) but there was much to do at the h.o.m.ological Inst.i.tute.

More conferences were necessary, of course, to explain to his own laboratory group what was happening and why he had to take leave and how they were to continue their own projects without him. Then there was a much more elaborate arrival at Dallas with the essential equipment and with two young aides for what would have to be an open-ended stay.

Nor did William even look back, figuratively speaking. His own laboratory and its needs faded from his thoughts. He was now thoroughly committed to his new task.

It was the worst period for Anthony. The relief during William's absence had not penetrated deep and there began the nervous agony of wondering whether perhaps, hope against hope, he might not return. Might he not choose to send a deputy, someone else, anyone else? Anyone with a different face so that Anthony need not feel the half of a two-backed four-legged monster?

But it was was William. Anthony had watched the freight plane come silently through the air, had watched it unload from a distance. But even from that distance he eventually saw William. William. Anthony had watched the freight plane come silently through the air, had watched it unload from a distance. But even from that distance he eventually saw William.

That was that. Anthony left. He went to see Dmitri that afternoon. "It's not necessary, Dmitri, for me to stay, surely. We've worked out the details and someone else can take over."

"No, no," said Dmitri. "The idea was yours in the first place. You must see it through. There is no point in needlessly dividing the credit."

Anthony thought: No one else will take the risk. There's still the chance of fiasco. I might have known.

He had had known, but he said stolidly, "You understand I cannot work with William." known, but he said stolidly, "You understand I cannot work with William."

"But why not?" Dmitri pretended surprise. "You have been doing so well together."

"I have been straining my guts over it, Dmitri, and they won't take any more. Don't you suppose I know how it looks?"

"My good fellow! You make too much of it. Sure the men stare. They are human, after all. But they'll get used to it. I'm I'm used to it." used to it."

You are not, you fat liar, Anthony thought. He said, "I'm not "I'm not used to it." used to it."

"You're not looking at it properly. Your parents were peculiar--but after all, what they did wasn't illegal, only peculiar, only only peculiar. It's not your fault, or William's. Neither of you is to blame." peculiar. It's not your fault, or William's. Neither of you is to blame."

"We carry the mark," said Anthony, making a quick curving gesture of his hand to his face.

"It's not the mark you think. I see differences. You are distinctly younger in appearance. Your hair is wavier. It's only at first glance that there is a similarity. Come, Anthony, there will be all the time you want, all the help you need, all the equipment you can use. I'm sure it will work marvelously. Think of the satisfaction--"

Anthony weakened, of course, and agreed at least to help William set up the equipment. William; too, seemed sure it would work marvelously. Not as frenetically as Dmitri did, but with a kind of calmness.

"It's only a matter of the proper connections," he said, "though I must admit that that's quite a huge 'only.' Your end of it will be to arrange sensory impressions on an independent screen so that we can exert-- well, I can't say manual control, can I?--so that we can exert intellectual control to override, if necessary."

"That can be done," said Anthony. "Then let's get going....Look, I'll need a week at least to arrange the connections and make sure of the instructions--"

"Programming, " said Anthony. "Well, this is your place, so I'll use your terminology. My a.s.sistants and I will program program the Mercury Computer, but not in your fashion." the Mercury Computer, but not in your fashion."

"I should hope not. We would want a h.o.m.ologist to set up a much more subtle program than anything a mere telemetrist could do." He did not try to hide the self-hating irony in his words.

William let the tone go and accepted the words. He said, "Well begin simply. We'll have the robot walk."

A week later, the robot walked in Arizona, a thousand miles away. He walked stiffly, and sometimes he fell down, and sometimes he clanked his ankle against an obstruction, and sometimes he whirled on one foot and went off in a surprising new direction.

"He's a baby, learning to walk," said William. Dmitri came occasionally, to learn of progress. "That's remarkable," he would say.

Anthony didn't think so. Weeks pa.s.sed, then months. The robot had progressively done more and more, as the Mercury Computer had been placed, progressively, under a more and more complex programming. (William had a tendency to refer to the Mercury Computer as a brain, but Anthony wouldn't allow it.) And all that happened wasn't good enough.

"It's not good enough, William," he said finally. He had not slept the night before.

"Isn't that strange?" said William coolly. "I was going to say that I thought we had it about beaten."

Anthony held himself together with difficulty. The strain of working with William and of watching the robot fumble was more than he could bear. "I'm going to resign, William. The whole job. I'm sorry....It's not you."

"But it is is I, Anthony." I, Anthony."

"It isn't all all you, William. It's failure. We won't make it. You see how clumsily the robot handles himself, even though he's on Earth, only a thousand miles away, with the signal round trip only a tiny fraction of a second in time. On Mercury, there will be minutes of delay, minutes for which the Mercury Computer will have to allow. It's madness to think it will work." you, William. It's failure. We won't make it. You see how clumsily the robot handles himself, even though he's on Earth, only a thousand miles away, with the signal round trip only a tiny fraction of a second in time. On Mercury, there will be minutes of delay, minutes for which the Mercury Computer will have to allow. It's madness to think it will work."

William said, "Don't resign, Anthony. You can't resign now. I suggest we have the robot sent to Mercury. I'm convinced he's ready."

Anthony laughed loudly and insultingly. "You're crazy, William."

"I'm not. You seem to think it will be harder on Mercury, but it won't be. It's harder on Earth. This robot is designed for one-third Earth-normal gravity, and he's working in Arizona at full gravity. He's designed for 400 C, and he's got 300 C. He's designed for vacuum and he's working in an atmospheric soup."

"That robot can take the difference."

"The metal structure can, I suppose, but what about the Computer right here? It doesn't work well with a robot that isn't in the environment he's designed for....Look, Anthony, if you want a computer that is as complex as a brain, you have to allow for idiosyncrasies....Come, let's make a deal. If you will push, with me, to have the robot sent to Mercury, that will take six months, and I will take a sabbatical for that period. You will be rid of me."

"Who'll take care of the Mercury Computer?"

"By now you understand how it works, and I'll have my two men here to help you."

Anthony shook his head defiantly. "I can't take the responsibility for the Computer, and I won't take the responsibility for suggesting that the robot be sent to Mercury. It won't work."

"I'm sure sure it will." it will."

"You can't be sure. And the responsibility is mine. I'm the one who'll bear the blame. It will be nothing to you."

Anthony later remembered this as a crucial moment. William might have let it go. Anthony would have resigned. All would have been lost.

But William said, "Nothing to me? Look, Dad had this thing about Mom. All right. I'm sorry, too. I'm as sorry as anyone can be, but it's done, done, and there's something funny that has resulted. When I speak of Dad, I mean your Dad, too, and there's lots of pairs of people who can say that: two brothers, two sisters, a brother and sister. And then when I say Mom, I mean and there's something funny that has resulted. When I speak of Dad, I mean your Dad, too, and there's lots of pairs of people who can say that: two brothers, two sisters, a brother and sister. And then when I say Mom, I mean your your Mom, and there are lots of pairs who can say that, too. But I don't know any other pair, nor have I heard of any other pair, who can share both Dad Mom, and there are lots of pairs who can say that, too. But I don't know any other pair, nor have I heard of any other pair, who can share both Dad and and Mom." Mom."

"I know that," said Anthony grimly. "Yes, but look at it from my standpoint," said William hurriedly. "I'm a h.o.m.ologist. I work with gene patterns. Have you ever thought of our gene patterns? We share both parents, which means that our gene patterns are closer together than any other pair on this planet. Our very faces show it."

"I know that, too."

"So that if this project were to work, and if you were to gain glory from it, it would be your gene pattern that would have been proven highly useful to mankind--and that would mean very much my gene pattern as well....Don't you see, Anthony? I share your parents, your face, your gene pattern, and therefore either your glory or your disgrace. It It is mine almost as much as yours, and if any credit or blame adheres to me, it is yours almost as much as mine, too. I've is mine almost as much as yours, and if any credit or blame adheres to me, it is yours almost as much as mine, too. I've got got to be interested in your success. I've a motive for that which no one else on Earth has-- a purely selfish one, one so selfish you can be sure it's there. I'm on your side, Anthony, because you're very nearly me!" to be interested in your success. I've a motive for that which no one else on Earth has-- a purely selfish one, one so selfish you can be sure it's there. I'm on your side, Anthony, because you're very nearly me!"

They looked at each other for a long time, and for the first time, Anthony did so without noticing the face he shared.