Colon are friends of long standing on the Ankh-Morpork City Watch (police force.) Colon is overweight and whenever possible avoids exertion. Nobbs, who is about 34 years old, is skinny, smelly, and usually taken for a dwarf. He is in fact, a human. He chain smokes without exhaling. They are first seen in this novel standing guard at the Water Gate, allowing Mr. Pin and Mr. Tulip, the story's villains, free access to the city because it is too much trouble to climb the icy steps. The friends often engage in philosophical conversations, in which Nobby picks flaws in Colon's comments, forcing him to come up with quick answers. Colon gives protagonist William de Worde items for his newspaper for drinks but insists on ample praise for the Watch's vigilance in apprehending wrongdoers.