The year is 1142, and all England is in the iron grip of a civil war. And within the sheltered cloisters of the Benedictine Abbey of Saint Peter and Saint Paul, there begins a chain of events no less momentous than the political upheavals of the outside world. First, there is the sad demise of Richard Ludel, Lord of Eyton, whose ten year old son and heir, also named Richard, is a pupil at the Abbey.

Supported by the Abbot Radulfus, the boy refuses to surrender his new powers to Dionysia, his furious, formidable grandmother. A stranger to the region is the hermit Cuthred, who enjoys the protection of Lady Dionysia, and whose young companion Hycacinth, befriends Richard. Despite his reputation for holiness, Cuthred's arrival heralds a series of mishaps for the monks.

When Richard disappears and a corspe is found in Eyton forest, Brother Cadfael is once more forced to leave the tranquility of his herb garden and devote his knowledge of human nature to tracking down a ruthless murderer.