On a boat departing Paris in 1840, a young man, Frédéric Moreau, stares moodily at Paris, still visible behind him. He is going home to Nogent-sur-Seine to stay with his mother before beginning his law studies. On deck, he observes a man holding forth with a young woman. Frédéric and the man soon engage in conversation. The man introduces himself as Jacques Arnoux, the owner of an art magazine. A servant tells Monsieur Arnoux he is needed by Mademoiselle, and he goes belowdecks.
Frédéric observes the passengers. He sees a beautiful woman in the first-class section and is captivated. Everything about her entices him—from her body to her basket of embroidery. Frédéric sees that her shawl is about to fall into the water. He grabs it for her, and she thanks him. Then Arnoux appears with a small girl. The beautiful woman is Arnoux’s wife.
Frédéric stays close to the Arnouxes. Arnoux invites him to go belowdecks, to the saloon. There, Frédéric sits near Madame Arnoux and observes her closely. Eventually, Frédéric and the Arnouxes get off the boat, and Frédéric says goodbye. As he makes his way home, he remembers that Monsieur Arnoux had called his wife “Marie.” He vows to become a friend of the family and see Madame Arnoux again.
At home, Frédéric’s mother and some friends greet him warmly. Madame Moreau welcomes her son and is certain that great things await him. As Frédéric eats a meal, he wonders what Madame Arnoux is doing. He eventually leaves the house to visit a friend named Charles Deslauriers.
Deslauriers’s father was angry and abusive when Deslauriers was a child, but he sent him to school in Sens, where he met Frédéric. Deslauriers was passionate about philosophy, while Frédéric was interested in drawing and writing. They planned to work together in Paris and lead decadent lives with women. They separated for a while, while Charles studied law in Paris and Madame Moreau sent Frédéric to Le Havre to visit a rich uncle.
This is the first time they have seen each other in two years. Deslauriers tells Frédéric he will not be staying in Paris, which disappoints Frédéric. Frédéric tells Charles about Madame Arnoux, and Charles encourages him to pursue a friendship with Monsieur Arnoux.