Edward d'Eath, scion of a down-and-out noble family, is determined to track down the lost heir to Ankh-Morpork's throne, and place him as leader, no matter how many people he has to take out to do it.  Meanwhile, Captain Samuel Vimes, commander of the Ankh-Morpork City Watch, is confronted by new problems. About to be married to Sybil Ramkin, richest woman in Ankh-Morpork, he's got to deal with the Watch's new recruits first: a dwarf and a troll, representatives of two races involved in a grudge so old it doesn't need excuses anymore, and a...woman who is, most of the time, human. He's also got to figure out who stole a mysterious device from the Ankh-Morpork Assassin's Guild, and who's been committing a string of gruesome, seemingly random murders.

Possibly the best Watch book, it sees the most turbulent time in their history since tha last one (that bloody great big dragon). Vimes is getting married, there's trouble between the Dwarfs and the Trolls and someone has stolen a mysterious artifact called a Gonne. Vimes really is in full Dirty Harry mode in this book, he's full of indignant wrath and fury as his life is changing and he's not sure how to handle it. The watch gets some new recruits too: namely a troll, a dwarf and a werewolf who's also a woman. Fred and Nobby aren't sure how they'll cope especially as the watch suddenly starts to get larger and larger as they soak up all the fighting trolls and dwarfs into an uneasy alliance. The crime is of course eventually solved and a greatful Patrician reluctantly agrees to enlarge the watch even further and promote Vimes to Commander (as well as lob him a gong) and Carrot becomes the new captain of the watch.