An outbreak of yellow plague spreads through Exeter while John’s brother William becomes seriously ill. At the same time, a sequence of brutal deaths appears to be connected with a revival of religious dissent in the city.
Cathedral canons use the epidemic and murders to demand action against alleged heretics, but John doubts that doctrine alone explains the killings. His refusal to support indiscriminate persecution makes him a target of ecclesiastical authority, and he must seek sanctuary while continuing to identify the person using fear of disease and heresy as cover for murder.