Following a vision by young monk Brother Columbanus, the monks of Shrewsbury go to Wales to recover the bones of St Winifred and take them to the abbey. But their attempted bribery of the Welsh puts them at odds with the local residents - and when the local landowner is found murdered, the monks are regarded as prime suspects. It takes Cadfael's intervention and mediation to smooth things over and allow them to return home.

The murder of wealthy cleric, Peter Clemence, an envoy of the king on his way to Chester, leads the finger of suspicion to point to a new monk at the Abbey, Meriet Ashby. Cadfael investigates at the behest of the abbot, on whom political pressures are being piled from the civil war raging round England. Cadfael uncovers a tangled web of family loyalty, dishonesty & unrequited love.

Cadfael's novice, Brother Oswin, is found close to death, babbling about a woman, out in the woods in mid-winter. Cadfael goes out to try to find out what happened to him and the small traveling party he had met up with, when he finds one of them, a young nun called Sister Hilaria, raped, murdered and encased in the ice of a frozen stream. Suspicion of her murder falls on Oswin, who is no state to convincingly deny it. Cadfael tracks down the two other members of the party, Ermina and Yves Hugonin, and sets out to prove Oswin's innocence.