Men at Arms reunites us with the stalwart defenders of our beloved Ankh-Morpork: the Night Watch. Along the way we also meet up with some of the Discworld's most distinctive secondary characters (including Foul Ole Ron and Big Fido), get a glimpse of affirmative action Ankh-Morpork-style, discover the identity of the rightful king (if Ankh-Morpork still had a king, which it doesn't, which isn't the fault of the shady characters in this book trying to replace the Patrician with the aforementioned heir to the throne, who doesn't want the job anyway), converse once more with Gaspode the talking dog, and - if that's not enough - make ready for the wedding of the year between Captain Samuel Vimes of the Night Watch and Lady Sybil Ramkin, proprietor of the Sunshine Sanctuary for Sick Dragons and the richest woman in Ankh-Morpork. Captain Vimes is in fact retiring from the Watch, but his retirement involves much more than the traditional gift watch presentation from his men. A washed-up aristocrat named Edward D'eath takes it upon himself to restore the long-lost monarchy, a circumstance that can only come about over the Patrician's dead body. Even clowns aren't safe from this deadly conspiracy.
The trouble begins with an explosion and robbery at the Guild of Assassins. Someone has stolen nothing less than the only "gonne" on Discworld, and a series of murders shock the town. OK, nothing's really going to shock the people of Ankh-Morpork, but the fact that people keep turning up full of holes where guts should be definitely stirs up the Watchmen. The Patrician is also less than happy about things, so he makes sure the Watch gets to the bottom of things by forbidding Captain Vimes to investigate. The Watch itself is growing; thanks to some new laws pushed through by the Silicon Anti-Defamation League, it has ethnically balanced itself with the addition of a dwarf, a troll, and a woman to the force. The woman, Angua, also happens to be a werewolf, and I don't have to tell you that dwarfs and trolls are natural enemies. Luckily, Constable Carrot, the 6'6" dwarf (he was adopted, you know) who is just so doggoned nice that people will actually listen to him and do as he requests, is there to keep the Watch united and performing its duty the way Carrot (alone) thinks it should be done. After a dwarf is killed and a troll arrested by the Day Watch (on the basis that any troll is surely guilty of something), there's an ever-present danger that the city's trolls and dwarfs will have a go at each other (and it won't be like last time, when both groups somehow managed to ambush one another at the same time).
Constable Detritus really steals the show here. Watching a troll think is always entertaining, but Detritus really comes into his own as this story progresses. At first, he can't salute without knocking himself out, but by the end he's recruiting and training fellow trolls (in his own endearing way) and warming up quite well to his dwarf partner. He also manages to show us that, in the right conditions (such as the kind of very cold temperature you find in a pork futures market), trolls can be brilliant thinkers.
People always die in Discworld novels, but there was one death in Men at Arms that really took me by surprise. A bit sad, it was. Don't be sad about Captain Vimes leaving the Night Watch, though. Furthermore, don't worry about the future of the City Guard, as it does not fall into the hands of Sergeant Colon or Corporal Nobbs (who, as we all know, has already been disqualified from the human race for shoving). I'm sure the men and women and dwarfs and trolls and werewolf of the Night Watch will be as ready as ever for the next threat that rears its ugly head in Ankh-Morpork; after all, Carrot's still on the job.