In A.D. 670, an Irish merchant ship is attacked by a pirate vessel off the southern coast of the Breton peninsula. Merchad, the ship's captain, and Bressal, a prince from the Irish kingdom of Muman, are killed in cold blood after they have surrendered. Among the other passengers who manage to escape the slaughter are Fidelma of Cashel and her faithful companion, Brother Eadulf. Once safely ashore, Fidelma--sister to the King of Muman and an advocate of the Brehon law courts--is determined to bring the killers to justice, not only because her training demands it but also because one of the victims was her cousin. The only clue to the killer's identity is the symbol of the dove on the attacking ship's sails, a clue that leads her on a dangerous quest to confront the man known as The Dove of Death.