Vimes will hear it first as a shuffle in the dark: the footsteps of a large man in impractical shoes, the shifting-clothing sounds of a heavily fringed leather jacket. As they draw closer to each other, those steps slow. The rustling falls quiet. The other man in the catacombs has gone still, hand pressed to the stone of an alcove, waiting in the deep shadow.

Hide, hisses a tight-coiled corner of his thoughts. Burrow into the dark like a mouse from a predator. Pray that it cannot see you.

You are not a mouse, says another voice. Ignore him. Take up space. Square your shoulders and brace for whatever dares to hunt you.

Melt into the shadows, says a third. Make this your ambush.

It doesn't matter yet: he has no way of seeing in the dark. To Vimes, the man ahead is clearly lit. He's on the ragged end of middle-aged, broad-shouldered as a boxer and unremarkably tall. His clothing is a mashup of cowboy costume and cheap sequins, and he wears it alongside unruly facial hair and the permanent flush of a long-time alcoholic. He isn't visibly armed.

And he plainly can't see Vimes. The man stands frowning into the dark, head half-cocked to listen, doggedly watchful as a soldier or a cop.