A C-47 transport plane, named the Corsair, makes a forced landing in the frozen wastelands of Labrador, and the plane's pilot, Captain Dooley, must keep his men alive in deadly conditions while awaiting rescue.

Canadian Mountie Steve Wagner captures a German Luftwaffe officer on a spy mission, who later escapes from the prison camp. To catch the spy ring, the Mounties employ a ruse so that the spies, believing Steve to be sympathetic, enlist him in their plans.