While Frédéric is in Nogent, Deslauriers reviews some of his legal documents involved with his intended job for Dambreuse. Deslauriers decides that he himself should have this job—and have Madame Arnoux. Imagining himself to be like Frédéric, he visits Madame Arnoux under the pretext of discussing the loan Frédéric had made. He declares his love for her, and she laughs at him. Humiliated, Deslauriers tells her Frédéric is getting married, which shocks her. Alone, Madame Arnoux realizes she is in love with Frédéric.
In Nogent, Frédéric and Louise get to know each other. Louise tells him she is in love with him and asks him to marry her. Frédéric hesitates, then says he will. At home, he receives letters from Dambreuse, asking him to dinner; Deslauriers, suggesting that he stay in Nogent; and Rosanette, asking for money. He decides to go back to Paris and think.
Frédéric is unhappy in Paris. He wants to marry Louise, especially because of Roque’s wealth, but he feels this would prove his weakness. Mademoiselle Vatnaz visits, compliments the good taste of his possessions, and tells him Rosanette wants to see him. She tells him that Rosanette is now with the wealthy Prince Tzernoukoff. Mademoiselle Vatnaz declares her love for the actor Delmar.
Frédéric visits Rosanette and gives her the money she’d asked for in her letter. Rosanette had requested this money as a ruse to see him again. She invites him to the sea, but Frédéric bristles at the thought of hiding from her rich lover.
One day, Frédéric runs into Madame Arnoux on the street. They talk briefly, and then Frédéric goes to see Deslauriers. Deslauriers tells him that he told Madame Arnoux he was getting married and that she had been shocked. Deslauriers reveals that Senecal has been freed from prison and that Dussardier is giving him a party.
At the party, the guests discuss politics and the state of France, where more and more freedoms are being restricted. Hussonnet is there, and he is civil to Frédéric, saying nothing about the article he wrote for Le Flambard. Afterward, Dussardier walks home with Frédéric and Deslauriers, and the two men try to convince Frédéric to buy Rosanette’s portrait from Pellerin and to let go of his anger. Frédéric gives in. Deslauriers is glad that Frédéric has decided not to take the job for Dambreuse.
Louise had requested that Frédéric procure two statues for her, so he goes to Arnoux’s factory to get them. Madame Arnoux is there, and she speaks bitterly of Frédéric’s forthcoming marriage. She hints that she is angry at his involvement with Rosanette. Frédéric denies both the affair and his impending marriage and confesses he is still in love with her. He kisses her eyelids and vows never to marry. Madame Arnoux is surprised and happy. Frédéric makes more wild claims about his feelings for her, and she sends him away. But he continues to visit her at her country home, gaining her trust, and they continue to see each other. They do not become lovers, but they envision a wonderful life together.
Frédéric treads carefully, still hoping that she will agree to become his mistress. He gets impatient. He is not happy that Arnoux suspects nothing, and he begins resenting Madame Arnoux. One afternoon, when her little son, Eugene, is sick, Frédéric convinces her to meet him in a few days on the street, to walk together in public. He plans to seduce her, and he rents a small apartment that he plans for them to duck into during their walk. On Tuesday, the day he expects her, he waits for hours, but she does not arrive. There are riots in the streets on that day, as the working class simmers and revolution is on the horizon, and he suspects they have kept her away.
Meanwhile, Madame is at home, frantically caring for Eugene, who is very sick. She sits with him through the night as he gets worse and worse. He eventually improves, and she decides that this was a warning. She will not continue her association with Frédéric.
The demonstrations have led to a greater energy, and a reformed government seems to be imminent. Frédéric dismisses his love for Madame Arnoux and visits Rosanette. He takes her to the apartment he’d rented for Madame Arnoux, and they finally become lovers.
When Deslauriers connives to take over Frédéric’s job and love, he proves himself to be far from the docile, pathetic friend he has sometimes appeared to be. Until this point, Frédéric has dismissed and welcomed Deslauriers according to his whims, trading his friend for whatever better thing came along, whether it was a more beneficial connection, a woman, or his own personal goals. Deslauriers has been loyal, often hurt by Frédéric’s capriciousness but always ready to forgive. Deslauriers’s attempts to take over Frédéric’s life fail; his conscience stops him from visiting Dambreuse, and his attempts to woo Madame Arnoux are met with laughter. However, he does manage to exert some power over Frédéric’s life when he tells Madame Arnoux that Frédéric is to be married. Although this eventually works in Frédéric’s favor in that it helps Madame Arnoux to realize her own feelings, the fact that he is willing to sabotage Frédéric’s affairs is a significant betrayal.
Among the men in Frédéric’s world, being rivals does not preclude feeling sympathy and even affection for one another. As Frédéric works to win over Madame Arnoux, he feels an attraction to Arnoux because of their similarities. Deslauriers feels as though he almost becomes Frédéric as he goes to visit Madame Arnoux. These affections and similarities are not the sort that occur between ordinary friends. Instead, in both cases, one party is actively trying to steal something—Madame Arnoux—from the other: Frédéric wants to steal her from Arnoux, and Deslauriers wants to steal her from Frédéric. Although the men are rivals, competing for the same prize, both aggressors feel sympathy and connection to their victims. These feelings do not logically fit the situations, and they suggest something that all the men, on some level, know: each of them will lose Madame Arnoux, and, perhaps, none of them really had her in the first place.
When Frédéric’s love of Madame Arnoux flares up again and, for the first time, he manages to actually forge a romantic relationship with her, his delight in her and in their future is so effusive that it foreshadows a disastrous conclusion. Frédéric, who tends toward extremes, claims that he cannot live without her. For her part, Madame Arnoux believes the love she feels is deserved because of her past bad luck. However, Frédéric has exhibited similar brash desires before: he wanted to come to Paris, to enter bourgeois society, to have wealth, to become Rosanette’s lover, and to earn favor with Dambreuse. In almost every case, when he achieved or came close to achieving what he desired, he no longer wanted it as strongly, or at all. Frédéric has proven to be more interested in the thrill of the chase than in the intended goal, and now that Madame Arnoux is within reach, it seems unlikely that he will be satisfied.
Although both Frédéric and Madame Arnoux curse fate for their inability to live together as a couple, the only thing keeping them apart is Madame Arnoux’s reluctance to commit adultery and Frédéric’s determination that he must wait for her to change her mind. Their world is full of people who are involved in various affairs—nearly everyone they know has a lover, a mistress, or some sort of illicit admiration for someone forbidden. Frédéric and Madame Arnoux complain about fate, but, alone in the country with no possibility of being discovered, it is more likely something within themselves that stops them from pursuing their affair any further. Frédéric wants Madame Arnoux to come to him of her own accord, but the fact that he waits so passively suggests that he, too, is hesitating and is all too willing to find an excuse to hold back. He does make an effort to conquer her by arranging a walk and secretly renting a streetside apartment, but these efforts are invisible to her and instead serve only to increase Frédéric’s frustration. When Madame Arnoux fails to show up and decides that her son’s illness was a sign from God, she is quick to swear off the affair—and Frédéric is just as quick to run to the arms of Rosanette.