Mutz Greenbaum directs this 1940s adventure based on the story by Rudolph Cartier. When a group of idealistic freedom fighters led by Karel Langer (Anton Walbrook) pitch up in World War II France following Franco's triumph in the Spanish Civil War, they are distraught to find themselves designated political prisoners by the collaborationist Vichy government. Dispatched to work for the Germans building a railway in the Sahara, the men anticipate a long and brutal period of enslavement. However, one of the men manages to escape and sets out for London with vital information on the war. Will he manage to carry his message to the Allies?