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 St. Peter and St. 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 Eaton, whose 10-year-old son and heir, also named Richard, is a pupil at the abbey. The boy refuses to surrender his new powers to his formidable grandmother; supported by Abbot Radulfus, Richard defies the furious Dionysia.

A stranger to the region is the hermit Cuthred, who enjoys the protection of Lady Dionysia, and whose young companion, Hyacinth, befriends Richard. Despite his reputation for holiness, Cuthred's arrival heralds a series of mishaps for the monks. When Richard disappears and a corpse 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.