What Vimes has been spending all his money on; half his pay, in fact, in the days when he was still on the edge of alcoholism. Stupid onion-chopping ninjas!
The moment when Carrot brings Angua's body back to the Yard. He's heard that only silver really kills werewolves, but he doesn't know for sure, and he's very scared. And then he does the chores around the Yard. Because it's his turn to do them.
Which is simultaneously both a very "Carrot" thing to do, and (thanks to the narrative pointing out how unpredictably humans react to grief) one of the most humanizing things that almost-too-good-to-be-believed Carrot has ever done.
Any thoughts for poor Edward d'Eath? Intelligent and innovative but utterly trapped by his social class and pitiful finances... only to end up in a cycle of mad delusion that takes him even further downward. Right to his ignoble death at the hands of someone he thought he could trust.