In 1349, Oswald de Lacy was an 18-year-old novice monk at Kintham Abbey. Sent to collect herbs from the forest, Oswald comes across a terrified village girl who attempts to frown herself. Oswald returns her to the local village, only to discover that several other women have disappeared. A heinous killer is at work, and Oswald vows to find him—but in this fifth outing (after The Bone Fire), he will uncover a secret that haunts him for the rest of his life.