The population of Gwynedd includes both humans and Deryni, a race of people with inherent physic and magical abilities who are being systematically persecuted by both the Crown and the Church.

The novel begins after the invasion of Prince Marek Furstán-Festil, the bastard child of the last Deryni ruler of Gwynedd, King Imre, and his sister, Princess Ariella.

Word of the invasion is quickly sent to Rhemuth, where King Rhys Michael Haldane has spent the first six years of his reign as an imprisoned puppet of his lords of state.

When a Torenthi herald arrives at Rhemuth to challenge the king, the great lords realize that they must permit Rhys Michael to go to Eastmarch and personally respond to the invasion.

Disguised as one of Queen Michaela's serving maids, Rhysel Thuryn quickly learns of the king's plans to accompany his army to Eastmarch.

Rhysel meets with members of the Camberian Council and attempts to convince them to activate the king's Haldane potential before he leaves the following day.

In a private conversation, Lady Sudrey, Hrorik's Deryni widow, offers Rhys Michael her support and the use of her limited powers.

Dom Queron Kinevan rushes to the king's side, but he does not arrive in time and Rhys Michael soon dies from poor medical treatment.

As the army returns to Rhemuth with Rhys Michael's body, the Camberian Council informs the northern lords of the king's death and offers their assistance in securing the rights of the new Regents.

Accompanied by Queron, Tieg, Ansel MacRorie, and a band of armed men, Graham and Sighere confront the great lords inside the royal tomb.