Following a slight accident, a stranger appears in a Provençal village and knocks at the door of the Philippes'villa, asking them for help. Albert Philippe is suspicious but his wife shows some interest in the man. After leaving the Philippe family, the unknown man goes to the village, meets the mayor and buys an island opposite the Philippe villa. It suddenly appears that the mysterious fellow is none other than Balthazar Lemonnier, a well-known millionaire. No sooner is the news disclosed than everybody, including the initially distrustful Mr. Philippe, wants to become his friend.

Bienaimé, a modest postman, in love with Janine, the village postmistress, does not know that he is the illegitimate son of the old Baron de Mondésir. The Baron dies and in happy amazement, Bienaimé finds he is the sole heir to the deceased's estate. But he should be careful, for two crooks, Waldemar and Erika, are after his newly-acquired wealth.

Noël Bienvenu, owner of a career, is a widower and lives with his parents. His son Bastien, whom he despises, was sentenced to six months in prison for theft. Noël goes to see a dying friend, Romieux, who asks him to take care of his daughter Marthe, who has settled in Paris (Batignolles district). Noël goes there and discovers that Marthe is destitute (her lover Gaston being an incarcerated mobster): he then offers her to come and live with him and soon, marries her.