Neale and Pedro fly cargo between Chungking and Calcutta. When their buddy Bill is murdered they investigate. Neale meets Bill's fiancée Virginia and becomes suspicious of a deeper plot while also falling for her charms.
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.