In the 12th-century Benedictine monastery of Shrewsbury, Brother Cadfael has settled down to a quiet life in charge of the herbarium after an adventurous, and far from monastic, youth. But when his prior determines to acquire the bones of a saint from a remote Welsh village, Cadfael's worldly experience becomes vitally important. It is fortunate indeed that his skills as a herbalist are matched by his prowess as a detective, since the obstacles to the expedition include murder.