Cambridge, 1940. It is the first winter of the war, and snow is falling. When an evacuee drowns in the river, his body swept away, Detective Inspector Eden Brooke sets out to investigate what seems to be a deliberate attack. The following night, a local electronics factory is attacked, and an Irish republican slogan is left at the scene. The IRA are campaigning to win freedom for Ulster, but why has Cambridge been chosen as a target? And when Brooke...