John Frankenheimer's The Train

During WWII as Allied forces approach Paris in August 1944 German Colonel Von Waldheim secures a train to transport France's greatest paintings to Germany amid the chaos of retreat. The French resistance ordered by London not to destroy the treasures tasks station master Labiche with preventing the theft. After his friend is killed trying to stop the train and a conversation with a hotel owner Labiche resolves to save the antiquities by staging an elaborate ruse to keep the train from leaving French territory.