Continuing Kurtz's longstanding fantasy series about the magic-powered Deryni, who live not altogether comfortably among humans in the medieval, Welsh-flavored monarchy of Gwynedd. After a wearisome recap of the historical and political backdrop, we learn that Prince Conall, King Kelson's cousin, has secretly arranged for the Deryni Tiercel to awaken his magical powers. (All members of the Haldane royal family have this potential.) Gradually, though, Conall falls into evil ways: Tiercel, after an argument with Conall, tumbles to his death; Conall reads the dead brain for information, then conceals the body. Meanwhile, King Kelson and his blood-brother Dhugal depart on a trip to search for relics of the legendary Saint Camber. Conall, tagging hopefully along, poisons Dhugal's wine; when in due course there's an accident on the trail, Kelson and Dhugal vanish and are given up for dead. Conall's father Nigel takes up the reins of power. But then Tiercel's body is discovered, and Nigel suspects Conall's involvement. In a panic, Conall blasts Nigel with mental power. So, with Nigel comatose and apparently dying, Conall becomes king in all but name--he even marries Kelson's intended bride! Then Kelson shows up alive, having been inspired by a vision of Saint Camber--and the stage is set for a magical showdown. Formulaic, self-referential, and a trifle cumbersome; still, series fans who thrive on Kurtz's patient detail and steady storytelling will find the usual reading pleasures here.