February, AD 668, and Cashel is full of distinguished visitors. Under the old Irish custom, Fidelma of Cashel and Eadulf of Seaxmund's Ham, having been joined together for a year and a day, are to be married. But on the eve of the ceremony, the pious Abbot Ultan is found murdered in his chamber. Worse still - one of the most distinguished guests, the King of Connacht, is seen fleeing from the scene and charged with the murder. He demands his right to appoint Fidelma in his defence. Fidelma soon discovers that Abbot Ultan is not the pious man he was thought to be - indeed, many of the guests have cause to hate him. It is a long weekend of suspicion, fear and more death before Fidelma and Eadulf are able to reveal the truth behind Ultan's murder.