An introduction to the history, folklore, and liturgy of the Celtic people explores the Celtic contributions to Christianity and illuminates the Celtic way of prayer through a collection of early Irish litanies, Welsh poems, and blessings.

Counseling a hostile Irish delegation to the Celtic church of 670 A.D., Fidelma of Cashel is embroiled in a politically tenacious investigation when one of the delegates is found murdered, a case that is complicated by the theft of a priceless reliquary.