AllMovie

The Maginot line, designed to be the deepest war trench in the world, provides the focus for this espionage drama. The French began building the trench during WW II. It did not matter that trench warfare had proved to be terribly ineffective during WW I, the French were determined to make it work. It didn't. The Germans simple drove their tanks around the complex maze and invaded France. The story in the film begins as the new Line commander is murdered by a machine gun. Three lieutenants are the prime suspects. One of them is a German spy. He is soon discovered by counterintelligence agents who pursue him to a blind corner in the trench. Though he is only 200 yards from the German border, the spy kills himself.