The third part begins with an overview of Léon’s time in Paris. He was somewhat popular with women, but he didn’t really get caught up in the hedonism of the city. He thought of Emma often, in the three years that passed, but the memory of her slowly faded. Now, though, all his feelings have returned in full. He regrets having once missed his chance. Now, full of a new confidence, he is determined to have her.
Léon’s determination to seduce Emma resembles Rodolphe’s, a few chapters earlier. It’s a determination that has little to do with Emma herself; it is driven not by love but by self-image. Léon wants to sleep with Emma because it would make him feel like a man, a protagonist—it would confirm that he has grown beyond what he was when he couldn't have her.
The day after the performance, he visits Emma at her hotel. They talk about their boredom and misery, but they don’t tell each other anything in particular. They both conceal their romantic histories, and Léon pretends that he’s pined for Emma all this time. They reminisce about their earlier friendship, and Emma feels “astonished at being so old.” Léon’s memories fill out her idea of her own past, so that it seems more complete and more appealing.
Emma and Léon pick up where they left off – in the pretend world of romantic melancholy. They still know nothing of one another’s actual lives, habits, or tendencies. Their relationship is built entirely on reinforcing one another’s fantasies of literary heroism. They treat one another like characters from books.
The room turns dark, and Léon implores her to start their love anew. She resists, because it is proper, but she is really filled with longing for him. She finds him very beautiful. She agrees to meet him the following morning at a nearby cathedral. After he leaves, Emma writes him a very long letter cancelling their meeting, but since she does not know his address, she decides to give it to him tomorrow.
The next morning, Léon comes to the cathedral early. He is full of joy, but the attendant is meddlesome and irritating, and Emma is late. When she finally comes in, she ignores Léon and begins to pray, which annoys him. The attendant insists on giving them a tour of the cathedral, but Léon drags Emma out by the hand; to her lingering doubts, her answers: “It’s what people do in Paris!” and pulls her into a cab. He shuts the blinds, and the cab circles town all day, until the horses are nearly dead of exhaustion. Emma raises the blinds just once, to throw away the torn pieces of her letter. In the evening, the cab drops her off at an inn.
The previous day, Emma and Léon’s actions were both modeled on romantic novels. But now they are acting within different frameworks. Emma is trying to follow the framework of virtuous resistance, the prudish prelude to adultery, as described in the novels. Léon is trying to follow a “Parisian” hedonistic framework, more openly skeptical of conservative morality. Neither framework is directly related to their actual feelings and desires.