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.

The tumultuous loves of a diver and a pretty bitch. Mario loves Perrucha, she only loves money. When, by dint of diving, the boy's health deteriorates, the girl goes to find an important industrialist. Such a story can only end badly and Mario strangles Perrucha.