In 1360, Edward III issues a call to arms, as attacks by the French threaten to turn into a full-blown invasion. Cambridge is already tense, and then the first murder occurs—of a French scholar living in the town. Physician Matthew Bartholomew is called upon to investigate mysterious deaths in a nearby hospital, and he quickly realizes that there is something odd about the inmates and their keepers—something dark and deadly. Pressure mounts as the University and the town clamor for answers, leading Bartholomew and Brother Michael in a frantic quest for a solution before the powder-keg of animosity in Cambridge is ignited.