They began meeting in Scott's quarters in the fourth week.
There was no discussion of whether to meet. No proposal, no vote, no moment at which anybody said, we should do this. Spock simply arrived at 2200 on a Thursday with a padd, and found McCoy already there, and Uhura came in eleven minutes later without knocking, and Scotty poured six glasses of something and put one in front of Spock, who did not touch it, and one in front of Galloway, and one in front of Ensign Brandt, the other man from that landing party, who took the same chair every Thursday and drank from the glass exactly as often as Galloway did.
Galloway looked at it. "Sir, I'm on at 0400."
"Ye're on at 0400," Scotty agreed, and did not take it back.
Galloway sat down and did not drink it and did not move it, and neither did Brandt. And the two glasses sat in front of the two of them at every meeting for the next two years, full, untouched, and Scotty poured them both every time and never said a word about either.
"Right," said Scotty. "Who's got anything."
Nobody had anything.
"Mister Spock?"
"I have eliminated four approaches."
"Which four?"
"Controlled slingshot, direct. Controlled slingshot with a stellar mass under one point four solar. Transporter-mediated displacement using the Guardian's residual field as a carrier. And an approach involving deliberate replication of the original distortion wave, which I abandoned after nine hours because it requires a source of chroniton radiation that does not exist within four hundred light years and would, if it did, sterilize this vessel."
"Four," said McCoy.
"Four."
"In a month."
"In twenty-six days, Doctor."
"And that's progress."
"That is four fewer things to try, which is not the same as nothing. And if you intend to make that face at me every Thursday for the foreseeable future, I would ask you to at least vary it."
McCoy did not smile. Nobody smiled.
They sat in an engineer's quarters at 2200 on a Thursday with a bottle and six glasses and a padd, and it went on for fifty minutes, and at the end of it they had exactly what they had come in with. Then they got up and went to their quarters and got up in the morning and did their jobs.
They did it again the next Thursday. They did it every second Thursday for two years, and it was, for four of the six of them, the only thing they lived for, and not one of them ever said so.
* * *
It was McCoy who ran the histories, in the end, because it was the one part of the work that needed no physics.
He did it the way Spock had taught him to, years before, on another impossible afternoon, when a twentieth-century pilot named Christopher had been sitting terrified in their sickbay and the only question that mattered was whether the man had left a mark on the world large enough that pulling him back out of it would tear something. Spock had gone into the records that day and come back with an answer: the pilot himself was no one, historically, a footnote with a clean service file. But his son, not yet born, would one day command the first Earth-Saturn probe, and that was a thread you did not cut. They had put Captain Christopher back that day with enormous care, exactly where they had found him.
So McCoy knew the method. He simply turned it on a different man.
He searched for James Kirk. Not the one he knew; the other one, the one who had fallen into 1930 and stayed. He searched every history the Enterprise carried, which was all of them, and he found nothing. No James Kirk of any weight anywhere. No inventor, no founder, no name in any index that mattered, in any field, in the whole of that century.
He found the woman, once he stopped hunting for greatness and started hunting for its absence. Edith Keeler, who in one version of the world had built a movement that bent a nation, had in this one run a mission on Twenty-first Street for a single year and then, in the summer of 1931, simply closed it and walked away, and married a man of whom the record had nothing whatever to say, not a birthplace, not an origin, not so much as a middle name, and disappeared into a quiet life in Brooklyn.
And he found the son.
There was one. Samuel Kirk, born 1935. And there was exactly one line about him anywhere in the whole of the machine, in a casualty roll that somebody had digitized a century and a half after the fact and no living soul had ever opened: killed in action, Korea, July of 1953, aged eighteen. No wife. No children. Nothing after him at all.
McCoy sat with that for a long time. Then he carried it to Spock.
"There is no Jim in there," he said. "Not anywhere. The most important man I ever knew, and history has not got so much as a hole where he stood, because he was careful. He was so careful. He spent forty years being careful, and he changed nothing that lasted, and the boy died before he could change anything either. There is not one Kirk left down there to alter so much as a bus timetable."
Spock looked at the record for a long moment.
"Then it is safe," he said, and his voice was perfectly level. And McCoy looked at him, and understood that this was the worst news either of them had ever been handed, and that it was at the same time the exact permission they had spent two years waiting for, and that the two things were one thing, and always had been.