Winter 1943, and US General Carnaby has been captured by the Nazis. He is being held in a fortress high in the Bavarian Alps. headquarters of the German Secret Service, and in his head are plans for the invasion of Normandy.

A special team of British commandos, a US Army ranger and a female secret agent is hurriedly assembled. Their mission: parachute into the area, break in to the alpine Castle, and rescue General Carnaby before the Germans can interrogate him.

But unknown to all, there is another mission, and someone in the group is a traitor...