In 1350, Cambridge lies ravaged by the Black Death. Crime flourishes too—three harlots are found with slit throats and branded feet, a friar dies rifling a strongbox full of college chronicles, and the Vice Chancellor of the University vanishes from his sick chamber with all its furnishings. Now the Chancellor calls on the deductive skill of Matthew Bartholomew, Master of Medicine. Busy enough already with the teaching and practice of new techniques, Bartholomew welcomes the investigative help of portly Brother Michael—a shrewd and merry monk, not unduly shocked by sins of the flesh. And soon—from an exotic poison to a surge of devil worship, from a grisly exhumation to a sweetheart's dying words—they are on a tangled and perilous trail of conspiracy and obsession.