Matthew Bartholomew travels to Ely with Brother Michael. Michael has been summoned to the city by his bishop, but it isn't until they arrive that they discover the reason – the bishop has been accused of murder. Almost immediately Michael discovers that there appears to have been a series of unexplained deaths in the area. At the same time Bartholomew comes across an underground movement of rebellion against the church and the tithes they demand from the laity, and the two men also learn that there has been a spate of burglaries which are being blamed on a band of travellers. Then a fellow of the priory is murdered almost under their noses. Can this death be connected to the others?