A thrilling mystery set against the backdrop of the Blitz in WWII England, by an Edgar Award–winning author.

England, 1941. Terror from the Germans' constant bombing is spreading through the nation, as homes, cities, and morale are reduced to little more than rubble. Worn down and defeated, British spirit teeters on a delicate seesaw.

When an insidious enemy strikes from within, the government is blindsided. Vital food supplies are destroyed and mysterious leaflets threaten imminent starvation. Department Z are called in to investigate—but soon find themselves locked in mortal combat with a ruthless, anonymous adversary who treats treason and murder like child's play.

How do you fight an unknown enemy? As deceit and betrayal mounts, the agents of Department Z find themselves in a race against time to uncover the conspiracy before there are deadly consequences.