Marthe, a robust peasant, is a single mother. For her child to be happy, she abandons him to the Duchemin household, eager for an impossible motherhood. Later, the young man is still unaware of the obscure sacrifice of his real mother.

The owner of the place of Chamonix covets the inn, run by the Michel's uncle, whose business goes bad. Michel decides to participate in a ski competition to help uncle.