40-year-old Vital, a shop workman in a textile mill, is chosen as a "guinea pig" by Alix, 25, a consultant who has come to the factory to conduct an ergonomic study. What this quiet and secretive man does not know (and what nobody knows for that matter) is that the young woman is actually the daughter of Baretti, the boss, on condition of anonymity. And what Vital did not expect (nor did anyone else) is that Alix would soon fall under his charm...