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. During WWI, two French soldiers are captured and imprisoned in a German P.O.W. camp. Several escape attempts follow until they are eventually sent to a seemingly inescapable fortress. + More