Vimes finds himself pressured by Lord Vetinari to solve the murder quickly, before inter-species war erupts in Ankh-Morpork. Vimes and Sergeant Angua visit the dwarves' under-city mine, where a nervous dwarf named Helmclever draws a mysterious sign in the spilled coffee on his desk. In a fit of his particular brand of omnidirectional anger, Vimes veers off into the mine where he cuts himself, he supposes, on a locked door. Later, he persuades the deep down dwarves to allow Captain Carrot to be the ""smelter"" who looks for the truth of the murder.