Hogan's scheme to help a German baroness escape to London is thwarted by the arrival of a new prisoner of war--- Colonel Crittendon--- whose repeated bungled attempts at escape are wreaking havoc on Hogan's mission to spirit away the baroness.

LeBeau aids in the escape of a captured French scientist and his daughter, who are able to make it out of Germany. But now the men of Stalag 13 must find a suitable "replacement" scientist who can present and discuss the study's findings.

The Germans' plan to shoot down British bombers by using captured RAF airplanes is uncovered, and Hogan and his men must attempt to destroy the aircraft before they can be flown on their deadly, deceptive mission.