While returning from a planning session in Scotland, Col. Gallagher's plane is shot down over the North Sea. He ends up in a rubber raft along with the only other survivor, Capt. Powell, a rich kid who happens to be a pilot Gallagher drummed out of the 918th because of a propensity to avoid danger. Now they wait out efforts by Allied rescue units to find them. Bad luck intervenes, however, and they are picked up by a German U-Boat. Surprisingly, Capt. Wessel, commander of the sub, treats them with gallantry and returns them to the island where he found them. Unfortunately, they soon discover that his intentions were far less than honorable as they become the bait in his trap.