"And the conflict between these neighborhoods—oh, but look; it is nearly midnight." Vetinari turned the little clock with its improbably complex mechanism toward Vimes to demonstrate. "Your wife will worry."

Ordinarily he would have protested—Sybil wasn't particularly a worrier, although she did seem to miss him when he was often out late; and that was enough to keep him protesting. He put the files down and rose to his feet (creaking a little; his age, catching up to him like always late at night). "You're right," he said. "Though she doesn't fuss."

"You should count your blessings, Commander."

"Oh, I do," Vimes said, too tired to watch his words: "The best part is when they care and you know they care and neither of you have to say anything."

"Oh, indeed," Vetinari said, and put the pen down, and looked at him for a very long time.

By this point Vimes was very, very good at unpacking levels of meaning, but he still must have made a mistake.

"Sir," he said: the safest weapon in his arsenal.

Vetinari lifted his hand to wave him out, smiling just enough to confuse. "Have a good evening, Commander."