What a communications officer does is not answer hails.
Anybody can answer a hail. What Nyota Uhura did, for eight hours a day, at a station eleven meters from a chair with the wrong man in it, was separate things.
A subspace band is not a line. It is a room, with everybody in it talking at once. There is a freighter's automated beacon, a colony's weather telemetry, somebody's mail to his sister, the long slow grinding of a pulsar four hundred light years off, and it all arrives on top of itself. An untrained ear hears noise. Uhura heard nine things and could name seven of them.
The trick, which could not be taught, and which Starfleet had spent forty years failing to teach, was that you did not filter.
Filtering is subtraction. Filtering throws away the thing you did not know you needed. What she did was hold all of it at once and pull it apart the way you pull apart a chord, and put each strand somewhere, and lose nothing.
* *
Galloway asked her about it once, at the end of a watch, in a turbolift, because he had heard the word filter used about her work and had understood that it was the wrong word and had not been able to say why.
"It is the wrong word," Uhura said. "Filtering is throwing things away. I do not throw anything away."
"Then what is it you do, Lieutenant?"
"I separate." The lift hummed. "Anybody can make a room quiet. What you want is somebody who can stand in a room with nine things talking at once and keep all nine, and lose none of them, and still tell you which one is real."
Galloway thought about that for three decks.
"That sounds like the whole job," he said.
*
On the eighth of March, in the twenty-second month, a distress call came in off the Beta Aurigae relay degraded to about nine percent, with two other transmissions lying across it. A freighter beacon. A piece of somebody's mail.
Standing procedure was to filter to the strongest carrier and request a repeat. Standing procedure would have taken twenty minutes and the ship on the other end of it did not have twenty minutes.
Uhura did not filter.
It took her four minutes and she came out of it with all three, intact, including the mail, which nobody wanted and which she logged anyway, because discarding signal was not a thing she did.
Sixty-one people came off that transport.
Christopher Pike wrote it up as exemplary, in his own hand, and used the word extraordinary once, which he did not do. She read it a single time, and put it away.
She could take any two voices in the galaxy apart. That was the plain fact of her, and she knew it the way a surgeon knows about her hands.
*
There was one exception, and she had been working on it privately for four months.
She had something over three hundred entries by then. Every word accurate. Nothing behind any of them.
So she ran an experiment in her quarters, off duty, which she did not log and did not mention to anybody, and which she understood perfectly well while she was doing it.
She read an entry aloud.
Then she recorded herself reading it, and played it back, and listened the way she listened to everything, which is for the seam. For the place in the waveform where it stopped being James Kirk and became Nyota Uhura doing an impression of him.
She was hunting the seam because if she could find it she could work backward from it. That is the entire profession. You locate the boundary and you separate.
She did it thirty-nine times over four months with thirty-nine different entries.
She found the seam every time. It was in the same place every time. The place was the beginning.
There was no seam. There was nothing there to separate. It had been her voice from the first syllable of the first attempt, and there had never been anything else in the recording at all.
*
And then, in the fourth month, something happened that frightened her more than anything since a street corner in the winter of 1930.
She played back entry two hundred and nine, which is four words long, and she listened to her own voice say it.
And she thought: that is better than he said it.
She sat in her quarters in silence.
Because that is the shape of it. Not forgetting. Nobody forgets. What happens is that you keep the words and you put your own voice inside them, and it fits, and it is warm. After a while you stop noticing the substitution, and then one morning you catch yourself preferring it. And the man is gone, and you have replaced him with yourself, and you did it out of love, and there is no procedure anywhere for taking it back out.
She never ran the experiment again.
That night she opened the archive and wrote a line above entry one, in a hand that was not entirely steady.
Rule two. Do not read them aloud.
There had never been a rule one. She wrote it underneath, afterward, and it said: These are his. They are not yours.
* *
She went back on shift at 0800.
She sat down at her station and pulled a garbled colony transmission into four clean component parts inside a minute, and routed all four, and said "Aye, sir" to Christopher Pike twice before lunch in a voice that did nothing at all.
She was the finest communications officer in Starfleet.
She could take anything in the universe apart.
She could not get him out of her own mouth.