 The population of Gwynedd includes both humans and Deryni, a race of people with inherent physic and magical abilities who have been shunned and persecuted for centuries.The novel begins three months after the events of "Deryni Checkmate", as young King Kelson Haldane struggles to resolve an internal ecclesiastical schism on the eve of an invasion by a powerful Deryni sorcerer.The novel takes place in June and July 1121, less than a year after the coronation of fourteen-year-old King Kelson Haldane.