After three days of sulking, Count Muffat returns to Nana and finds her troubled about religious matters. She tells him openly that she is afraid to die because she knows what happens to "unmarried women who had anything to do with men" and also because dead people are so ugly. These discussions renew Count Muffat's religious fears. Consequently, he and Nana spend some time comforting each other.
Two days later, Count Muffat arrives and discovers that Nana is terribly sick because she has had a miscarriage. Zoé found her the day before in a pool of blood and Nana has been confined since then. When Nana sees Count Muffat, she smiles and pretends that she wanted the child because it was Muffat's. Actually, she has no idea who the father was. She queries Muffat about why he came and soon discovers that he is deeply troubled. Suddenly Nana realizes that Rose has sent the letter and that Count Muffat now knows all about his wife's infidelities.
At first Count Muffat declares that he is going to challenge Fauchery to a duel, but Nana points out the disgrace connected with such an act. After pacifying him somewhat, she finally tells him that he is mainly bothered by the fact that he is deceiving his wife in the same way that she deceived him. She tells him: "That's why you're stamping about here in my bedroom instead of killing both of them." She also points out that if he makes a scene, she would become the subject of many derogatory remarks throughout Paris. She advises him to make up with his wife and only continue to see her at intervals.
Count Muffat later admits that he is also troubled by financial matters. A note he signed is being passed around for collection, and he dares not sell any of his property because the transaction would require his wife's signature.
Meanwhile, Countess Sabine wants her daughter's marriage contracts signed as soon as possible so that she can give a party celebrating it and at the same time show off how she has had her house newly decorated. At the party, all of the old guard are shocked at how radically Countess Sabine has altered the old family mansion. Most of the ladies present also think Estelle de Beuville could have made a better match than Daguenet. Then other gossip occupies the ladies' attention.
La Faloise arrives and begins talking to Steiner, Foucarmont, and others. He suddenly proclaims that Nana has arrived; the group of men look surprised before they realize that la Faloise is trying to be witty. He then ends by asserting that it really was Nana who arranged the wedding.
When Fauchery arrives, la Faloise attempts another joke by wondering aloud if the countess has good thighs. Fauchery is visibly disturbed by this allusion even though he calls la Faloise an idiot. As the gay waltz from The Blond Venus is playing, Fauchery goes to pay his respects to the count and the countess. Many eyes in the audience are upon Fauchery when he approaches his hosts, but nothing out of the ordinary occurs.
After the church wedding, the count enters the countess' bedroom for the first time in two years. He suggests selling some of their mutual property. Since the countess also has great need of money, she readily agrees.
At two o'clock in the afternoon, Daguenet appears in Nana's bedroom. Since she has forgotten the bargain she made with him, he has to remind her that he is there to give her his "innocence" on his wedding day.
Nana's basic sexuality is again emphasized by the opening sentence of this chapter, which describes Nana in bed with Count Muffat. Nana suddenly expresses her fear of God and her fear of death, which begins to prepare the reader for her actual death in the final chapter. Nana's fear that "people are ugly when they're dead" also prepares us for the awesome ugliness of Nana's own death.
As Count Muffat sinks deeper and deeper into the gutters of Nana's filth, he tries more and more to recall his previous religious training. When he receives the letter which his wife had written to her lover, he realizes the depth of his own degradation. Nana's one (and perhaps only) intuitive comment comes when she tells the count: "It's that you're deceiving your wife, too. You don't sleep away from home for nothing. . . . She's only following your example. . . . That's why you're stamping about in my bedroom instead of killing both of them."
Finally, Nana is able to make a dent in Count Muffat's immense wealth. He now finds himself in financial troubles, but Nana is unsympathetic and unrelenting in her demands for more money. Equally important is the fact that the Countess Sabine, in learning the pleasures of adultery, has also learned from Nana the pleasures of being needlessly extravagant. In the first part of the book, the countess had been adamant about not changing the ancestral mansion. Now that she is becoming as corrupt as Nana, she is also becoming as capricious and demands that the entire mansion be redecorated. Thus, Nana's influence even extends so far as to affect the countess' personal behavior.
In earlier chapters, Nana had quietly obtruded upon the parties given by the aristocracy. In this chapter, her intrusion is more blatantly felt. The waltz from The Blond Venus has become the theme song of the aristocracy. Nana is openly discussed by the aristocratic ladies and analogies are made connecting the countess' caprices with Nana's. There are even jokes made by the men concerning the manner in which Nana has arranged the marriage between Daguenet and Estelle. The final change is ironically underscored when Fauchery enters to the tune from The Blond Venus and calmly greets his mistress and her husband. After the party, when the count mentions the need to sell some joint property, the countess, who is now corrupted, readily agrees because her love affairs are proving to be expensive also.
The comic ending of the chapter underscores the corruption of the entire society as Daguenet comes to sleep with Nana on his wedding day.