The summer of 1273 is peaceful for most of England, except in the village of Tyndal, where Martin the cooper has been poisoned at the local inn. Martin had enough enemies, so the killer could be anyone. This crime has nothing to do with the priory, but Prioress Eleanor grieves for her friend, the newly bereaved Crowner Ralf, and offers what help she and former apothecary Sister Anne can. But when her own problems multiply, Eleanor has good reason to regret her kindness.