A shy, penniless employee of the garage owner Grillot, the gentle Louis wins $10 million in the lottery. Flitting along the banks of the Seine, he takes in Raoul Grandvivier, an unknown, untalented painter who has just botched a spectacular suicide intended to draw attention to himself. Raoul takes him back to his studio, where he meets his charming daughter Lucie. In order to see Lucie again, with whom he is in love, Louis offers to sell the paintings. In reality, he's the one paying for them, to make it look like a wealthy art lover.
 Fernand Gravey
Raoul Grandvivier
 Pierre Mondy
Le maître nageur
 Jacques Dufilho
Jules Grandvivier
 Darry Cowl
Louis Stainval, laveur de voitures, gagnant à la Loterie
 Béatrice Altariba
Lucie Grandvivier, la fille de Raoul
 Julien Carette
Mr Grillot, le garagiste
 Suzanne Dehelly
Armande Grillot, la femme du garagiste
 Denise Carvenne
La caissière de la brasserie