A wrongfully convicted man finds himself suspected of a crime committed in his prison.

The mysterious vigilante Milton has warned Scotland-Yard of his intention to kill the lawyer Maurice Meister who is the cause of his sister's suicide. Police and detectives watch over the lawyer's home, but on the day and at the appointed time Meister is murdered.

Argan, the imaginary patient, allows himself to be led by his wife and his doctors who take advantage of his weakness. Only his daughter has sincere love for him. He ends up accepting that she should marry the one she loves and not the benet, son of an apothecary, whom he intended for her.

Le Bouif is a popular figure on the Parisian racetrack. He has the patter, the aplomb, the bonhomie, which allows him to pass on indestructible pipes to the racegoers. The amazement is general when he is accused of murdering the person of his son-in-law and then suspected of having suppressed the owner of a stable. Faced with the stubbornness of the examining magistrate, but helped by sympathetic young people, the Bouif proves his innocence and, back on the lawn, measures his popularity.