Tongues start to wag after a famous Parisian music hall dancer is rushed to hospital after being found poisoned by arsenic at the Concert Mayol.

Noël Rambert is overwhelmed by fate. Marthe, his wife, has left him. His son, little Jacques, sickly and touching, has psychic gifts. Life is not a happy one. A crime is committed. Poor Rambert is unjustly suspected. A good-looking man convinces him to confess his guilt. In doing so, he secures his child's future. Resigned to everything, the sad Rambert is ready for the scaffold. The little medium brings the truth to light and Mme Mortal denounces her husband, Daniel Mortal, the man behind the despicable bargain, as the murderer. Happiness returns with a bang, as the repentant Marthe Rambert continues to watch over little Jacques during the ordeal.

Maxime Bellac owns an art gallery. He has an affair with Michelle. One night when they have dinner together, Maxime tells Michelle he is forced to leave for the Canaries because of paintings. When they take a walk after their meal,a man suddenly appears, revolver in hand. In self-defense, Maxime kills him and,much to his surprise, recognizes a national security agent.Maxime confesses that he is in the pay of an eastern power; his mission is to get a file concerning Western nuclear weapons. Because of his crime, he cannot carry out his job; for Maxime's love, Michelle takes his place and becomes a spy.

The inhabitants of a small provincial town are requisitioned to take part in the French army's major maneuvers. A foreign spy takes advantage of these maneuvers to steal secret documents. The pursuit and capture of the spy and his accomplices are successfully carried out by all those taking part in the maneuvers.