Field Officer Sunniva Holm (Human, operations watch)

Holm had stood the operations watch on three posts and had never heard a Starwarden say paired callouts as if it were a thing a post ordinarily did, and had understood, by the twenty-fourth hour, that on this post it was.

It worked like this. The hull called a transaction — a thruster trim, a tether length, a time to hold station by — and the watch gave her the time from the upper housing and then the time from the lower, and the hull's master read both back, and the hull held from the first time to the second and did the thing at the second, so that whichever clock her own was nearer to, the thing was done inside both. Nobody on either end said which clock was right. Holm had asked, at the sixth hour, which one was right. The Starwarden had asked her whether she meant right at the housing or right at the hull, and had waited for the answer, and she had not had one, and he had gone back to his viewport as though that had been a reply.

By the twenty-ninth hour the figure was four minutes and one second, and the Fair Return lost lock.

It was not dramatic. Nothing on this post was permitted to be. The hull's master said, in a perfectly level voice, that her docking clock had stopped agreeing with her navigation clock by an amount she could not hold a tether to, and that her second had just told her a thing in an order the second swore he had not said it in, and that she would like, if the post did not object, to come in off the edge under callouts and not under her own instruments.

"Come in under callouts," the Starwarden said, from the viewport, without turning round. "Upper then lower. Say both back. Do nothing on either until you have said both."

So that was what the twenty-ninth hour was, and the thirtieth: a hull coming in by numbers it did not trust, off an edge it had been told was safe by a permit drawn from a figure that no longer obtained, with a man at the desk saying two times for every one thing and a woman four seconds away saying them back and then doing the thing. Holm logged each pair. She logged the point, in the thirtieth hour, at which the master's second came on and read back a pair in the wrong order, and the master's voice behind him saying upper, then lower, Teague, the man said both, and the pair read again.

The Fair Return made the inner marker at the thirty-first hour with four aboard and a tether she had cut to come in. Eight minutes later the window turned.

Holm had read about a turn and had never watched one. It was nothing. The figure between the two housings, which had been four minutes and nine, was fifty seconds, and then thirty, and then twenty-six, and sat there, and the lower housing was leading, by the twenty-six seconds it had always led by, as if the thirty-one hours had been a thing that happened to other instruments.

She wrote: Turn. 26 s. Lower leading. She looked at it. The Starwarden had still not come away from the viewport, and she wondered whether he would want the turn logged against the upper clock or the lower, and knew the answer, and logged it against both.