Ireland, A.D. 671. It is the beginning of the summer season and the Kingdom of Muman is preparing to celebrate the Great Fair of Cashel. It is an extravagant nine days of contests, food, and endless entertainment. Circumstances have led Fidelma and Eadulf far and wide across the kingdom, and they have been absent from the Great Fair for many years. But, for once they haven't been called away from Cashel, and are eager to enjoy the festivities - that is, until the last wagon in a group traveling to the fair catches on fire. The driver dies and it appears that the driver was a woman disguised a boy, for reasons unknown. Eadulf, upon further inspection, finds an even more disconcerting discovery - a rotting corpse in back of the wagon. Now, with only a week left to the fair, it is up to Fidelma and Eadulf to solve the mystery in time.