A bourgeois couple, proud of ancestral respectability, groom their only son Adolphe for a socially advantageous marriage, but he falls in love with Mathilde Anriquet, a modest office worker. The parents oppose the union, invoking rank, decorum, and a rival match with the exemplary Emilienne de Bégalit. The narrative traces familial tensions between duty and desire, contrasting conservative social codes with youthful individuality, and examines how class consciousness, parental ambition, and personal affection collide as the household confronts an unexpected challenge to its orderly expectations.