Vimes is sent as ambassador to Uberwald - a land of werewolves, vampires, and dwarfs - where a coronation is about to take place and old powers are manoeuvring for position. The Fifth Elephant of the title is a legendary beast from dwarf mythology, and its legacy has implications that reach back to Ankh-Morpork. Vimes out of his element, doing diplomacy with a clenched fist. Also the book where Angua's backstory comes into focus.