The incredible true story of how a bunch of writers, artists, set designers, and back room technicians pooled their talents in order to outwit the German High Command and fool Hitler. Espionage, counterespionage, decoy airfields, inflatable tanks, guns, and soldiers are all deployed in the run up to D-Day to create a massive diversion and the strongest possible indication that the landings will be in Calais rather than Normandy. A whole invisible army is conjured up: FUSAG, the First US Army Group. Major General Patton is placed in charge of this army, such is its importance he is detained in Britain for several weeks after the Normandy landings in order to successfully convince Hitler that a second and larger set of landings will be staged in Calais.