In the summer of 1144, a strange calm has settled over England--almost a peace. For several months there has been little actual fighting between the forces of King Stephen and those of Empress Maud, the two royal cousins contending for the throne.

On the whole, Brother Cadfael considers it a blessing to live in these peaceful times. Still, a little excitement--and some time spent outside the abbey walls--is always welcome. Cadfael is delighted when he is called upon to carry out a mission of church diplomacy to his native Wales; that his fellow traveler will be his young friend, Brother Mark, adds to his pleasure.

Shortly after their arrival, the two monks are caught up in a dangerous disagreement between Welsh princes. Owain Gwynedd has banished his brother Cadwaladr, accusing him of the treacherous murder of an ally. The rash Cadwaladr has landed an army of Danish mercenaries, poised to invade Wales and retake his lost lands.

Cadfael is captured by the Danes. His fellow prisoner is a headstrong young woman fleeing an arranged marriage--who may or may not have been involved in the murder of a prisoner in Owain's camp. The monk knows that chances of escape are slim. He has no hope of returning to Shrewsbury until a truce is declared or full-scale war breaks out--and a murderer is brought to justice.