Ireland, AD 670. The body of a young noble is found near Cashel, carrying few clues to his identity or purpose. Fidelma and Eadulf trace him to a militant religious movement whose leader is gathering disaffected followers and presenting political rebellion as spiritual renewal.
The murder leads beyond a private grievance into an organised threat to Muman. Fidelma must learn why the victim became involved with the movement and whether his death was intended to silence him, provoke the authorities or signal the beginning of a wider uprising.