In the year of our Lord 1145, the bitter rift between King Stephen and Empress Maud at last has a chance for reconciliation. A council takes place between the two sides that is hoped will resolve the question of prisoners of war. Brother Cadfael, ensconced in his herb garden at the Abbey of Saint Peter and Saint Paul, seeks leave to attend the crucial meeting. For he has learned that among the prisoners is one Oliver de Bretagne, a young man who calls upon loyalties even higher than Cadfael's monastic vows.'Before I was a brother I was a father,' Cadfael observes, and his determination to come to his son's aid prompts a perplexing investigation of a uniquely personal nature.