Before the landing in the normandy the allied forces sent a small special forces group to sabotage the german military. This operation "gambit" includes two allied soldiers dressing as german officers to gain information and sent it over to their headquarters. Cpt. Murphy, the leading officer in France for this mission, fears that this gambit - a pawn-sacrifice in chess - means his commando. The operation goes well initially but soon uncovers and Murphy has to flee to the underground. In the next phase parachuters are supposed to land there to execute the sabotage, but after nine of them landing the rest flies back due to D-Day being postponed because of bad weather. Now they are stuck in France on a suicide commando.