Gervase Bonel, with his wife and servants, is a guest of Shrewsbury Abbey of Saint Peter and Saint Paul when he is suddenly taken ill. Brother Cadfael hurries to the man's bedside, to discover that Bonel has been fatally poisoned.

After settling down to a quiet life, Cadfael finds his experience important when his Prior determines to acquire the bones of a saint from a Welsh village. The obstacles to the expedition include murder.

Brother Cadfael is asked to help identify a corpse found on Abbey Land and discovers that it is the least baffling facet of a mysterious murder.

In the Shrewsbury spring of 1140 the midnight matins at the Benedictine abbey reverberate with an unholy sound, a hunt in full cry. Pursued by a drunken mob, the quarry is running for its life. When the creature bursts into the nave to claim sanctuary, Brother Cadfael finds himself fighting off armed townsmen to save a young man.

In the summer of 1144, the Earl of Essex succumbs to a fatal arrow and his officials decide to save him from hellfire by restoring various properties he has annexed. The envoys arrive at the Abbey of St Peter and St Paul, then a murder is revealed.

The sheriff of Shropshire has been captured and the king taken prisoner. Then an exchange of prisoners is arranged - but before the exchange is completed, one captive is murdered. It is Brother Cadfael who first notices evidence of unnatural death.