The novel is set in the land of Gwynedd, one of the fictional Eleven Kingdoms. Gwynedd itself is a medieval kingdom similar to the British Isles of the 12th century, with a powerful Holy Church (based on the Roman Catholic Church), and a feudal government ruled by a hereditary monarchy. The population of Gwynedd includes both humans and Deryni, a race of people with inherent physic and magical abilities who have been brutally persecuted and suppressed for over two centuries. The novel begins approximately eight months after the conclusion of The King's Justice, as King Kelson Haldane embarks on a religious quest for relics of St.Camber to celebrate his knighting. When a deadly accident befalls Kelson's party, a close member of the king's family uses illicit arcane power to seize the throne of Gwynedd while his kingdom assumes he is dead. Kelson learns about his heritage while he battles for his survival and his heritage to Camber. When he finally returns to his kingdom he must battle his cousin who has taken over the throne, by using Haladane magic that was not his by right.