Nana suddenly disappears. After being seen in another of Bordenave's productions, she leaves without notifying anyone of her intentions. At a public auction, her house and furniture brought her over six hundred thousand francs. Various rumors circulate as to Nana's whereabouts, but no one can say for certain. In July, Lucy Stewart discovers that Nana is in a hotel dying of smallpox and is being attended by Rose Mignon.
Nana had returned from Russia and discovered that her child, Louiset, was dying of smallpox. She apparently caught the disease from her son while nursing him. Two days after Louiset's death, Nana came down with the disease.
At the hotel where Rose has Nana taken, various old acquaintances congregate to talk about Nana. The men remain below, frightened of the disease; even Count Muffat remains below, sending messages to inquire about Nana's progress. The women acquaintances, however, seem to have no inordinate fear of smallpox and join Rose even though by now Nana is already dead.
As the various friends discuss Nana's life and fortunes, they also comment upon the men who are gathered below. They are interrupted by the cries of people marching in the streets shouting patriotic slogans. The government has just declared war on Prussia, and Count Bismarck's name is mentioned by several of the assembled ladies.
Before Rose leaves, she places a candle by Nana's body. It illuminates Nana's face in such a way that the women see the horrors caused by the smallpox. Now Nana is "only a piece of carrion, a mass of pus and blood, a shovelful of putrid flesh. . . . It was as though the virus she had brought from the gutter, from the decaying carcasses left in the street, that ferment with which she had poisoned a whole people, had risen to her face and rotted it."
Outside, the people are still crying out for France to march on Berlin.
The final chapter of the novel offers again an indirect view of Nana as we hear of the rumors about her in foreign lands and then the reports of her terrible death agony. The weak and diseased body of her son succumbs to smallpox, and in nursing him, she contacts the disease. All throughout the novel, Zola has obliquely suggested that Nana's inner corruption is reflected in Louis' physical condition. His death ends then a part of Nana's corruption.
Since young Louis dies of smallpox, it is only natural that Nana die of the same disease. Zola apparently thought it would be poetic justice for Nana to die of a disease which would ravage her physical beauty. To die of some occupational disease like syphilis would be too contrived. Instead, the final view of Nana's decomposing body leaves the reader sick and disgusted: "She was only a piece of carrion, a mass of pus and blood, a shovelful of putrid flesh." Zola suggests that it was as though her inner rot and corruption had risen to the surface and covered her magnificent body with all its concealed filth and poison.
The novel ends with the people of the second empire clamoring for war, and we are reminded that the novel began with both the ladies of fashion and the ladies of the street wondering if Count Bismarck would make war on France. Here then is the beginning of the end to the second empire in France, which had engendered so much corruption in its own society.