He said, "No, I never heard of any Russian Zebatinsky. But then, I never heard of the American one either."

"Well," Brand scratched at his hairline over one temple and said slowly, "I don’t think there’s anything to this, but I don’t like to drop it too soon. I have a young lieutenant on my tail and you know what they can be like. I don’t want to do anything that will drive him to a Congressional committee. Besides, the fact is that one of the Russian Zebatinsky fellows, Mikhail Andreyevich Zebatinsky, is a nuclear physicist. Are you sure you never heard of him?"

"Mikhail Andreyevich Zebatinsky? No – No, I never did. Not that that proves anything."

"I could say it was coincidence, but you know that would be piling it a trifle high. One Zebatinsky here and one Zebatinsky there, both nuclear physicists, and the one here suddenly changes his name to Sebatinsky, and goes around anxious about it, too. He won’t allow misspelling. He says, emphatically, ‘Spell my name with an S.’ It all just fits well enough to make my spy-conscious lieutenant begin to look a little too good. – And another peculiar thing is that the Russian Zebatinsky dropped out of sight just about a year ago."

Dr. Kristow said stolidly, "Executed!"

"He might have been. Ordinarily, I would even assume so, though the Russians are not more foolish than we are and don’t kill any nuclear physicist they can avoid killing. The thing is there’s another reason why a nuclear physicist, of all people, might suddenly disappear. I don’t have to tell you."

"Crash research; top secret. I take it that’s what you mean. Do you believe that’s it?"

"Put it together with everything else, add in the lieutenant’s intuition, and I just begin to wonder."

"Give me that biography." Dr. Kristow reached for the sheet of paper and read it over twice. He shook his head. Then he said, "I’ll check this in Nuclear Abstracts."

Nuclear Abstracts lined one wall of Dr. Kristow’s study in neat little boxes, each filled with its squares of microfilm.

The A.E.G. man used his projector on the indices while Brand watched with what patience he could muster.

Dr. Kristow muttered, "A Mikhail Zebatinsky authored or co-authored half a dozen papers in the Soviet journals in the last half dozen years. We’ll get out the abstracts and maybe we can make something out of it. I doubt it."

A selector flipped out the appropriate squares. Dr. Kristow lined them up, ran them through the projector, and by degrees an expression of odd intent-ness crossed his face. He said, "That’s odd."

Brand said, "What’s odd?"

Dr. Kristow sat back. "I’d rather not say just yet. Can you get me a list of other nuclear physicists who have dropped out of sight in the Soviet Union in the last year?"

"You mean you see something?"

"Not really. Not if I were just looking at any one of these papers. It’s just that looking at all of them and knowing that this man may be on a crash research program and, on top of that, having you putting suspicions in my head – " He shrugged. "It’s nothing."

Brand said earnestly, "I wish you’d say what’s on your mind. We may as well be foolish about this together."

"If you feel that way – It’s just possible this man may have been inching toward gamma-ray reflection."

"And the significance?"

"If a reflecting shield against gamma rays could be devised, individual shelters could be built to protect against fallout. It’s fallout that’s the real danger, you know. A hydrogen bomb might destroy a city but the fallout could slow-kill the population over a strip thousands of miles long and hundreds wide."

Brand said quickly, "Are we doing any work on this?"

"No."

"And if they get it and we don’t, they can destroy the United States in toto at the cost of, say, ten cities, after they have their shelter program completed."

"That’s far in the future. And, what are we getting in a hurrah about? All this is built on one man changing one letter in his name."

"All right, I’m insane," said Brand. "But I don’t leave the matter at this point. Not at this point. I’ll get you your list of disappearing nuclear physicists if I have to go to Moscow to get it."

He got the list. They went through all the research papers authored by any of them. They called a full meeting of the Commission, then of the nuclear brains of the nation. Dr. Kristow walked out of an all night session, finally, part of which the President himself had attended.

Brand met him. Both looked haggard and in need of sleep.

Brand said, "Well?"

Kristow nodded. "Most agree. Some are doubtful even yet, but most agree."

"How about you? Are you sure?"

"I’m far from sure, but let me put it this way. It’s easier to believe that the Soviets are working on a gamma-ray shield than to believe that all the data we’ve uncovered has no interconnection."

"Has it been decided that we’re to go on shield research, too?"

"Yes." Kristow’s hand went back over his short, bristly hair, making a dry, whispery sound. "We’re going to give it everything we’ve got. Knowing the papers written by the men who disappeared, we can get right on their heels. We may even beat them to it. Of course, they’ll find out we’re working on it."

"Let them," said Brand. "Let them. It will keep them from attacking. I don’t see any percentage in selling ten of our cities just to get ten of theirs – if we’re both protected and they’re too dumb to know that."

"But not too soon. We don’t want them finding out too soon. What about the American Zebatinsky-Sebatinsky?"

Brand looked solemn and shook his head. "There’s nothing to connect him with any of this even yet. Hell, we’ve looked. I agree with you, of course. He’s in a sensitive spot where he is now and we can’t afford to keep him there even if he’s in the clear."

"We can’t kick him out just like that, either, or the Russians will start wondering."

"Do you have any suggestions?"

They were walking down the long corridor toward the distant elevator in the emptiness of four in the morning.

Dr. Kristow said, "I’ve looked into his work. He’s a good man, better than most, and not happy in his job, either. He hasn’t the temperament for teamwork."

"So?"

"But he is the type for an academic job. If we can arrange to have a large university offer him a chair in physics, I think he would take it gladly. There would be enough nonsensitive areas to keep him occupied; we would be able to keep him in close view; and it would be a natural development. The Russians might not start scratching their heads. What do you think?"

Brand nodded. "It’s an idea. Even sounds good. I’ll put it up to the chief."

They stepped into the elevator and Brand allowed himself to wonder about it all. What an ending to what had started with one letter of a name.

Marshall Sebatinsky could hardly talk. He said to his wife, "I swear I don’t see how this happened. I wouldn’t have thought they knew me from a meson detector. – Good Lord, Sophie, Associate Professor of Physics at Princeton. Think of it."

Sophie said, "Do you suppose it was your talk at the A.P.S. meetings?"

"I don’t see how. It was a thoroughly uninspired paper once everyone in the division was done hacking at it." He snapped his fingers. "It must have been Princeton that was investigating me. That’s it. You know all those forms I’ve been filling out in the last six months; those interviews they wouldn’t explain. Honestly, I was beginning to think I was under suspicion as a subversive. – It was Princeton investigating me. They’re thorough."

"Maybe it was your name," said Sophie. "I mean the change."

"Watch me now. My professional life will be my own finally. I’ll make my mark. Once I have a chance to do my work without – " He stopped and turned to look at his wife. "My name! You mean the S."