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.
Set in Ireland in 671 C.E., Tremayne's 26th Sister Fidelma mystery (after 2015's The Devil's Seal) has one of the author's craftiest setups. After a strange wagon joins up with some traveling entertainers en route to perform for the Great Fair of Cashel, it suddenly bursts into flame. The driver, a girl disguised as a boy, may have set the wagon on fire. She jumps off the burning vehicle, runs a few paces, then collapses and dies. After the conflagration is extinguished, the wagon is found to contain a rotting corpse of a man, who turns out to have been poisoned by the same substance that caused the girl's death. Brother Eadulf, Fidelma's longtime companion, witnesses these dramatic events; he quickly informs her of what's transpired and begins to question other witnesses. The former religious sister is troubled when she learns that the entertainers have not been straight with her. Eadulf disappears in a subplot that distracts from the main story, and the payoff doesn't match the intriguing opening.