Following The Chronicles of the Deryni and The Legends of Camber of Culdi, Kurtz begins another fantasy trilogy--again set in the modestly appealing and fairly persuasive medieval, hierarchical, Welsh-flavored state of Gwynnedd. (This world, you'll remember, is sustained by a strong church and inhabited by a mixture of humans and human-alien, psi-powered Deryni.) Young Kelson, Deryni king of Gwynnedd, has loyal advisers--Deryni warrior Morgan, Deryni bishop Duncan, boyhood blood-brother Dhugal. But they're all threatened by a Deryni-hating coalition led by former archbishop Loris and Caitrin, aging pretender-queen of Meara. Complex, fairly deft plotting ensues: Loris horribly executes the Kelson-appointed bishop of Meara;in retaliation (the winter snows prohibit full-scale military action) Kelson captures Caitrin's heirs, boorish prince Llewell and comely, shy princess Sidana--whom Kelson threatens to wed Meanwhile, in a major subplot, Dhugal discovers that he has Deryni-style mental powers, eventually realizing that he is Duncan's long-lost son. And, with hard-working characterization and tense confrontations (if little real action), this encore is likely to satisfy Gwynnedd veterans without tempting too many newcomers.