Baron Herbert's return from the Crusades should have been a joyous occasion. Instead, he grows increasingly morose and withdrawn. When his sons begin to die in strange accidents, some suspect a malign presence at the baron's storm-blasted castle. When the baron suddenly sends for Sir Hugh of Wynethorpe, begging his friend to bring spiritual and secular healers, Sir Hugh is concerned and persuades his sister, Prioress Eleanor of Tyndal Priory, to accompany him as well as a respected physician, Master Gamel. Although he is pleased when the prioress brings her healer, Sister Anne, he is dismayed that the group includes Brother Thomas, a man he has reason to despise. Tensions spark among family members and soon between those who came to help while Death's scythe harvests more victims.