The book begins when Conan is about forty-two, during his reign as the King of Aquilonia, and deals with a plot by a group of conspirators to depose him in favor of Valerius, heir to Conan's predecessor Numedides, whom he had slain to gain the throne. To accomplish this they resort to necromancy, resurrecting Xaltotun, an ancient sorcerer from the forgotten empire of Acheron. With his aid, the Aquilonian army is defeated by the rival kingdom of Nemedia and occupied. Conan, captured, is slated for execution until a sympathetic slave girl, Zenobia, risks her life to free him.