First Judah thinks the bounty man is human, but he accepts his commission with a guttural alien chuckle, flexes his neck and closes his eyes in ways that mark him as abnatural. He rides something that is not a horse but a vague equine semblance, the impression of a horse, a horse burr under the skin of the real. He shoots with a matchlock pistol that spits and mutters and is sometimes a rifle and sometimes a crossbow. He will not tell Judah his name.
They run together on their horse and their horse-bruise through the plainlands in the ripples of the rails, lands not colonised but infected, as life once infected rockpools. Four days of tracking with ideograms of hexed dust and the bounty-man finds Oil Bill, confronts him in a quarry. The white stone is marked, crosshatched with chisel lines, which make a grid behind the bandit's head.
--You, he shouts at Judah with the rage of the stupid betrayed, and the bondsman kills him and his weapons eat the corpse.
Iron Council, China Mièville, page 188-9