Night of the Lightbringer (Sister Fidelma Mysteries Book 28), Paperback/Peter Tremayne

This Sister Fidelma adventure begins on the eve of Samhain, AD 671, with a body found on an unlit pyre and a woman in a raven-feather cloak foreboding doom. Before long, the New Faith in the Five Kingdoms itself hangs in the balance, in this meticulously plotted continuation of the popular series.