In the autumn of 1140 the Benedictine monastery at Shrewsbury finds its new novice Meriet Aspley a bit disturbing. The younger son of a prominent family, Meriet is meek and biddable by day, but his sleep is rife with nightmares so violent that they earn him the name of "Devil's Novice". Shunned by the other monks, Aspley attracts the concern of Brother Cadfael. Then a body appears, that of a young priest last seen at the Aspley estate. Can Meriet be involved in the death? As events take a sinister turn, it falls to Brother Cadfael to detect the truth.