Barny, although a Marxist, is intrigued by the mysteries of religion. In confession, she teases a priest, Léon Morin, but he is a young and intelligent man and ready to discuss anything.
Young provincial Charles arrives in Paris to stay with his cousin Paul while studying law. Paul is a decadent, bohemian pleasure-seeker who shows the meek, diligent Charles the thrills of city life. When Charles falls for Florence, one of Paul's acquaintances, relationships begin to shift.
A bossy count has trouble marrying off any of his six sons. When one of them, Adam, finally makes wedding arrangements, something happens to his bride to be: she develops amnesia after an accident.