Captain Tom Reynolds and his band of skilled O.S.S. operatives are in WWII Burma to train the Kachin natives in modern warfare. But jungle combat, particularly against a Japanese army as familiar with the terrain as the Kachin, is more grueling than Reynolds had reckoned. Some respite is found in the arms of beautiful Carla Vesari, but after Chiang Kai-shek's Chinese rebels cross the border to loot and murder American soldiers, Reynolds abandons all notions of "military protocol" and seeks requital. He leads the remainder of his men into Nationalist Chinese territory for a fast retaliation — basically a wholesale slaughter. He is called on the carpet for this action later, and his would-be love, Carla is suddenly faced with a decision to stay with her current man or take off for the unknown USA with the American Captain.