The British stand alone against the Germans and the terror of their round-the-clock bombing. As homes and cities are reduced to rubble, morale teeters on a delicate seesaw. Then an insidious enemy strikes where least expected - from within. Vital food supplies are destroyed and the country is flooded with leaflets predicting imminent starvation. Racing against time, Britain's ultra-secret Department Z soon realizes it is in mortal combat with ruthless men, so power hungry that treason and murder have become their way of life.