Wat stopped climbing the tower ladders that spring, and did not announce it, and would have denied it if asked directly.
Thomas noticed because Wat began sending his apprentices up for inspections he had done personally for six years, always with a plausible reason attached — the boy needs the practice, I've the forge to mind, someone ought to check my judgment on the joint work anyway. It took a full month of plausible reasons before Thomas understood he was watching a man construct an elaborate architecture around a thing he refused to say.
He said nothing about it, which he later decided was correct, and waited.
Wat brought it up himself in the autumn, on a bad day, after his hip had locked coming up from the rail cutting and two of his own men had had to help him upright in front of half a work crew.
"I'm fifty-eight," he said that evening, without preamble, arriving at Thomas's door with a jug he had clearly already started. "Or thereabouts. Nobody wrote it down properly and my mother wasn't reliable on the point. Fifty-eight, give or take, which is old for a man who's spent forty years standing on stone in the cold."
Thomas got two cups.
"I can still forge," Wat said. "Hands are fine. Hands'll be fine for another ten years, I expect, and if they're not I'll know it before anyone else does and I'll stop before I ruin something." He drank. "It's the rest of it. Climbing. Kneeling. Getting up off the ground without an audience. I've been finding ways round it for two years and I've run out of ways."
"What do you want to do about it?"
"That's the thing, isn't it. I've been sitting with that question all summer and it keeps giving me the same answer and I keep not liking it." Wat turned the cup in his enormous scarred hands. "I want to teach. Full time. Give the physical works over to Osric's lad and two others I've been quietly training for a year and a half without telling anyone that's what I was doing, and spend what's left teaching every boy and girl in this valley how to actually build a thing properly instead of merely well enough."
"That's not a diminishment, Wat."
"It bloody feels like one." He said it flatly, without self-pity, as a statement of fact. "I know what it is objectively. I've watched Aldith do exactly the same thing and I told her at the time it was the best use of her that existed and I meant every word. It's different when it's your own knees telling you rather than your own judgment."
Thomas thought about a number in his tunic that had reached three, and about the difference between choosing an ending and being handed one.
"Can I tell you the thing I actually envy about it?" he said.
"Go on."
"You get to hand it over. Deliberately, in order, to people you chose and trained and can watch make mistakes while you're still here to correct them." Thomas turned his own cup. "I've written a succession document. It's a good document. It's also going to be opened by people in a room I'm not in, and every question they have about it will be a question nobody can answer. You're getting the version where you're present for it. That's not a small thing, Wat. That's most of what I'd want, if I got to choose."
Wat was quiet a long moment.
"That's a hell of a thing to put on a man who came here to complain about his hip."
"You came here to be talked out of feeling diminished. I'm declining to do that and offering you something else instead."
"Aye, well." Wat drank. "It's working, damn you, and I'd rather it wasn't."
He made the announcement to the council a week later, in about nine words, and refused to accept any thanks for forty years of work on the grounds that he wasn't dead and the fuss was premature.
He was, by every subsequent account, an outstanding teacher, and an absolutely merciless one, and the generation of builders that came up under him in his last decade could be identified anywhere in the March by the specific and unnecessary thoroughness of their joint work.