The name came up on the fourth day, in the mess, over breakfast, and it was Sulu who said it, without the slightest idea what he was doing.
"Commander Mitchell's putting in for the Constellation."
Spock did not move. He was sitting at the end of a table with a bowl of something he had not touched, because he had discovered in the last four days that he could not reliably remember whether he had eaten, and had begun, out of pure system, to sit in front of food at the appropriate times whether or not he intended to consume any.
"Say that again," he said.
"Sir?"
"The name, Lieutenant."
Sulu, who had served under this officer for two years and had never once been spoken to in that voice, put down his coffee. "Gary Mitchell. Exec on the Republic. He's putting in for the Constellation. It's all over the yard traffic."
* *
McCoy came into the mess a few minutes later and found four people at a table in silence, one of them a Vulcan with a padd, one of them Scotty with his hand over his mouth.
"What," said McCoy.
Nobody answered. He read the padd over Spock's shoulder.
MITCHELL, GARY. Lieutenant Commander. Executive officer, U.S.S. Republic. Current status: active. Fitness: excellent.
"He's dead," McCoy said.
"He is not dead."
"Spock, I signed the certificate." His voice went up. "Jim wrote the letter himself and then sat in my office for four hours and didn't say a word, and at the end of it he said, 'He was my friend for fifteen years, Bones,' and got up and went back to the bridge. So how is that man alive?"
"Because we never went to the barrier," said Uhura.
She had not touched her food either.
"That's it, isn't it, sir. The galactic barrier. In the history that happened, the Enterprise crossed it in 2265, under Captain Kirk, and nine people died and Commander Mitchell was one of them. In this one we didn't go. Because there was no Kirk to take us."
*
Spock set the padd down. "There are others."
"How many?" said Scotty.
"I do not know. I began three days ago and I have not stopped. Hear all of it before anyone speaks."
He did not look up.
"Gary Mitchell is alive. Elizabeth Dehner is alive; she published a monograph last year on isolation psychosis in deep-space crews, and it is, I am told, very good. Anton Karidian is alive, touring the Federation with a company of actors, performing Macbeth to excellent reviews, and his daughter is nineteen and no one still knows she is protecting her father.
"Nine crewmen of this vessel who died between 2265 and 2267 are alive. I have the list. I am not going to read it out in a mess hall.
"On Eminiar VII a man named Anan Seven is still administering a computerized war that has run for five hundred and three years, and in the last two years three million people have walked into the disintegration chambers, because there was no Kirk to break the machines."
He stopped.
"And there is a colony that is not anywhere," he said. "Nivalis. Forty families. It failed in its second winter, and no ship came, and there is no record of it, because there was nothing left to record. I found it by the absence of a supply manifest that should exist and does not. I do not know how many others like it there are. I have no way to know.
*
Nobody spoke for a while. Pike had come in ninety seconds earlier and stopped inside the door and not announced himself, and nobody had noticed him.
And then Galloway, who had said perhaps a dozen words in three years, said:
"Sir. Permission to ask a question."
"Granted."
"How many are alive?"
Spock looked up. "Lieutenant?"
"You've named six people. You've said nine crewmen. Three million on Eminiar." Galloway's voice was flat, the voice of a man making a report. "And you're going to take that back. That's the operation, sir, and I've stood at doors for two years listening to officers not say it in a sentence, so I'll say it in one. We are going to go back and undo two years of a universe. And Mitchell dies. And Dehner dies. And nine of our own people. And three million on Eminiar walk into a box. And they are alive right now, sir, this morning, while we eat. So I'd like to know the number."
*
Spock did not answer at once. There were forty people in that room, and most of them had stopped talking.
He stood up. "Lieutenant. Come with me."
* *
They went to the observation lounge. Spock locked the door. Neither of them sat, and the starfield ran past outside.
"You have asked the correct question," Spock said, "and you are the only person aboard who has asked it, and I am aware of what that says about the rest of us. You want a number."
"Yes, sir."
"Three million four hundred thousand. Most of it on Eminiar and Vendikar. And I want to be precise: I do not know that number. It is an estimate. It could be low by half a million."
Galloway did not move. "And you're going to do it anyway."
"Yes."
"Why?"
And Spock said: "Because you have counted the living, Lieutenant. Carefully, and honestly, and you have brought me a number. Now count the others. How many people died in the last two years, in this universe, who would not have died?"
Galloway opened his mouth. And stopped.
"You cannot," said Spock. "Neither can I. We can see the people who are alive because Kirk fell out of the world, because they have names and records and we knew them. We cannot see the people who are dead because he fell out of the world, because in this universe they never came to anyone's attention. There was no Enterprise where an Enterprise was needed. Were there deaths for the want of it? I cannot know. No intervention, so no record of one, and no catastrophe on the books, because nobody went to look. Four hundred times, in two years, a starship did not arrive somewhere. Nivalis is one. I cannot count the rest.
"That is what an erased man leaves behind. Not an emptiness. An invisibility."
He put his hands flat on the table.
"So the arithmetic does not close. It has never closed. I am not going to decide this on the arithmetic."
"Then on what, sir?"
"On the difference between the two histories, which is not the same thing as the difference in their dead." Spock was quiet a moment. "Edith Keeler does not merely change lives. She changes whether the future forms at all. Her movement keeps a nation out of a war three years too long, and in those three years a man in Berlin finishes something, and there is no Federation, no Earth worth the name, no one of us ever born. That is a divergence of the whole civilization.
"Kirk's absence is not that. It is a variation inside a future that still arrives. Pike commands instead of Kirk. Mitchell lives, and others die, and the century is different in ten thousand particulars, and it still reaches the Federation. It is a real world, and a good one. And it exists only because one man walked out of history and put his shoulder against a door for forty years to hold it shut.
"And I find that I cannot draw pay in it, and eat in it, and call it a life."
The starfield went past.
Galloway stood on the other side of the table for a while.
"Permission to speak freely, sir."
"Granted."
"That's the worst reason I've ever heard."
"Yes," said Spock.
"And it's the only one that's any good." He came to attention. "I'd like it noted that I asked, and that you answered, and that you didn't lie to me, sir, which is more than I've had from anybody in nine years." He turned for the door. "I'll be at the back."