Pierre Tercelin who used to be a prosperous industrialist is now ruined and embittered, having become a mere lock keeper. A widower, he lives with his daughter Evelyne, a music-hall dancer. Claiming he is being persecuted by his cousin Edgar he gets in touch again with another cousin of his he hates, Bernard, a millionaire gun runner,who is also a victim of Edgar. It must be said that both Pierre and Bernard once caused Edgar to go bankrupt... Pierre offers Bernard to join efforts against Edgar....