Claude Gaspard is imprisoned following the false testimony of his wife that he had tried to murder her. He has four cellmates who are planning to escape and Claude is taken on board. They excitedly dig a tunnel which will lead to their freedom. On the eve of the chosen day of their escape, Claude is summoned to meet the director of the prison and is told that his wife has recanted and that he is a free man. After a skillful interrogation, Charles betrays his friends and reveals their escape attempt.