Emma was just like any other mistress; and the charm of novelty, falling down slowly like a dress, exposed only the eternal monotony of passion, always the same forms and the same language.
Emma and Rodolphe become more cautious, now meeting in the arbor in Emma’s garden rather than at Rodolphe’s house. Rodolphe quickly begins to tire of her; he finds her romantic idealism exhausting and loses interest in her. He continues the affair solely because of Emma’s beauty, but he urges her to act more cautiously. His attentions diminish, and she becomes less sure of his love. A letter from her father prompts a memory of her innocent childhood days. Emma begins to feel guilty and tries to redeem herself through sacrifice. She becomes cold to Rodolphe in order to end the affair, and she tries to force herself to love Charles.
Homais reads a paper praising a surgical procedure that will cure clubfoot. Under pressure from Emma (who hopes to help Charles’s career), Homais, and much of Yonville, the cautious Charles agrees to test this procedure on Hippolyte, a clubfooted servant at the inn. Although Hippolyte is more agile on his crippled leg than some men are on two healthy ones, he is talked into the operation by the townspeople. The attempt makes Charles a local celebrity—but it fails. Hippolyte’s leg develops gangrene and must be amputated. Emma judges Charles incompetent and feels disgusted by him. Although her affair with Rodolphe has slowed down considerably, she renews it now with even more passion than before.
Emma and Rodolphe’s affair begins where it left off. As Emma’s dissatisfaction with her marriage becomes even more pronounced, she begins to allude to the possibility of leaving Charles. Lheureux, the merchant and moneylender, begins to coax her into making extravagant and unwise purchases. She goes into debt to buy expensive gifts for her lover. Rodolphe, meanwhile, becomes still more easily annoyed by Emma’s romantic sentimentality and begins to lose patience with the affair. By now, Emma has been so careless that the whole town knows about her adultery. When Charles’s mother comes for a visit, she guesses it too. She and Emma fight, and Charles convinces Emma to apologize to his mother about the fight. After her apology, Emma is humiliated and begs Rodolphe to take her away. She plans to take Berthe with her. With the secret hope of running away with Rodolphe, she becomes more polite and much less irritable with Charles and his mother. The lovers finalize their plans. They decide that they will leave Yonville separately, then meet in Rouen. However, after a meeting in Emma’s garden, Rodolphe talks himself out of the idea.
As the affair progresses, it becomes increasingly clear that Rodolphe is interested in Emma solely for the sexual pleasure she affords him, and that Emma’s flights of romantic fancy are sorely misplaced. Emma is never able to remain happy in one situation for long, and her guilty attempt to reclaim her moral bearing by sacrificing herself for Charles’s career is simply the particular form her inevitable depression takes at this point in the story. When Charles characteristically bungles the operation, having allowed Emma and Homais to talk him into performing an unsound procedure on the crippled Hippolyte, Emma rediscovers her disgust for him and returns gladly to Rodolphe’s arms.
The operation on Hippolyte brings to light not only Charles’s incompetence, but also the real evil that pride and pretension can perpetrate on simplicity and innocence. Hippolyte is stupid and simple, but he is very able. Homais, on the other hand, is the picture of bourgeois pomposity. He loves to hear himself talk, regardless of the inanity of what he is saying. Combined with Charles’s incompetence, Homais’s know-it-all behavior invites the horrifying scourge of gangrene followed by the gruesome agony of amputation.
The story of Hippolyte can also be seen as an allegory for Emma’s life. By trying to alter a mediocre marital situation, Emma will in the end devastate both her family and their finances—much as the doctors destroy Hippolyte’s leg by trying to correct a condition that Hippolyte had previously accepted as part of his life. The nature of that destruction, a long, slow poisoning by gangrene, is similar to the long path of increasing adultery, immorality, and financial irresponsibility that Emma has taken.