A group of French soldiers, including the patrician Captain de Boeldieu and the working-class Lieutenant Maréchal, grapple with their own class differences after being captured and held in a World War I German prison camp. When the men are transferred to a high-security fortress, they must concoct a plan to escape beneath the watchful eye of aristocratic German officer von Rauffenstein, who has formed an unexpected bond with de Boeldieu.

Jean Gabinas Lieutenant Maréchal
Dita Parloas Elsa
Pierre Fresnayas Captain de Boëldieu
Erich von Stroheimas Captain von Rauffenstein
Julien Caretteas Cartier, the Vaudeville Performer
Georges Pécletas Officer
Jean Dastéas Teacher
Gaston Modotas Engineer
Christian Matras