Most of the river bed was a honeycomb crust of cracked mud. Currently the sun appeared to be a big copper gong nailed to the sky. The heat that had dried up the river fried the city by day and baked it by night, curling ancient timbers, turning the traditional slurry of the streets into a drifting, choking ochre dust.

It wasn't Ankh-Morpork's proper weather. It was by inclination a city of mists and drips, of slithers and chills. It sat panting on the crisping plains like a toad on a firebrick. And even now, around midnight, the heat was stifling, wrapping the streets like scorched velvet, searing the air and squeezing all the breath out of it.

High in the north face of the Assassins' Guildhouse there was a click as a window was pushed open.

Teppic, who had with considerable reluctance divested himself of some of the heavier of his weapons, took a deep draught of the hot, dead air.

This was it.

This was the night.

They said you had one chance in two unless you drew old Mericet as examiner, in which case you might as well cut your throat right at the start.

Teppic had Mericet for Strategy and Poison Theory every Thursday afternoon, and didn't get along with him. The dormitories buzzed with rumours about Mericet, the number of kills, the astonishing technique . . . He'd broken all the records in his time. They said he'd even killed the Patrician of Ankh-Morpork. Not the present one, that is. One of the dead ones.

Maybe it would be Nivor, who was fat and jolly and liked his food and did Traps and Deadfalls on Tuesdays. Teppic was good at traps, and got on well with the master. Or it could be the Kompt de Yoyo, who did Modern Languages and Music. Teppic was gifted at neither, but the Kompt was a keen edificeer and liked boys who shared his love of dangling by one hand high above the city streets.