Men at arms - a Discworld novel

'Be a Man in the City Watch! The City Watch needs Men!'. But what it's got includes Corporal Carrot (technically a dwarf), Lance-constable Cuddy (really a dwarf), Lance constable Detritus (a troll), Lance constable Angua (a woman...most of the time) and Corporal Nobbs (disqualified from the human race for shoving). And, they need all the help they can get. Because they've only got twenty-four hours to clean up the town and this is Ankh-Morpork we're talking about...