PREVIOUS BOOK IN SERIES: THE HABIT OF MURDER, ISBN 9781407967752. In 1360, sporadic attacks by the French threaten to turn into a full-blown invasion, and in Cambridge, fear of the enemy is magnified by the belief that foreign agents are lurking in the area. Amidst this atmosphere of swelling distrust, physician Matthew Bartholomew is called upon to investigate mysterious deaths in a nearby hospital. He quickly realizes that there is something something dark and deadly about the inmates and their keepers, which seems to be connected to the growing number of murders in the town. As pressure mounts and the town clamours for answers, Bartholomew must search for a solution before the powder-keg of animosity in Cambridge is ignited.