The novel is a collection of notebooks, found in the papers of the thirty-year-old historian Antoine Rokanten. The records were started in the early days of January 1932. The hero begins to keep a diary in order to understand what has changed in the surrounding world and almost immediately comes to the conclusion that he himself has changed. According to Rockanten, he is a man in whom the new is accumulated for years, and then breaks out, completely changing his whole life.
January 30, the hero sits in the cafe “Mably”. The owner of the institution, Monsieur Faskel, he describes as a person falling asleep alone with himself. Visitors to the cafe, in his opinion, are trying to stick together in order to “exist.” He himself is endlessly lonely: he lives alone, does not speak to anyone, and even with Francoise, the hostess of the cafe “The Shelter of the Routes,” makes love almost without words. At the same time, to join a society where everyone thinks the same thing, the hero can no longer.
In the diary entries, the protagonist of Nausea discusses his book about the Marquise de Rolbone and asks himself: did the latter take part in the murder of Paul I? Studying his reflection in the mirror, the hero realizes that his face is devoid of any expression. It is akin to the vegetable world, but not to the human world. Not finding Francoise in a cafe, the hero rolls Nausea. It retreats only with the immersion of Rocantena in the music.
Working on a book in the library, Rokanten meets Samouchka, a man who has been self-educated for seven years and is re-reading all books in alphabetical order for this. An unusual student comes to the hero to see the photographs taken by Rokanten during his trips, and pushes the latter to the idea that in his life there was not a single adventure.
On a Sunday afternoon the Boulevard is filled with a crowd of tourists, workers and citizens. The rich population of the city walks along the main street of Turnbread, filled with luxury shops. In the second half of the day, various social strata of Buleville are mixed together and begin to live together. Antoine Rokanten does not feel his belonging to them. He walks by the mole and awaits adventure, which turns out to be a feeling of irreversibility of time.
Periodically, in his records, the hero remembers Annie – a woman whom he once loved very much and has not seen for five years. On the eve of the fast, he receives a letter from her asking to meet. It awakens in him memories of the past. In one of the cafes he meets Monsieur Achilles – the same lonely as he and Dr. Roger – held in the life of a man.
Fog. Rokanten seems that the owner of the “Mably”, Monsieur Faskel died. It drives him crazy and does not work. The next day the hero learns that Monsieur Faskel has the flu. In the museum, Rokanten looks at the portraits of the ancestors of Buleville and understands that he is nobody: no grandfather, no father, no spouse, no voter, no taxpayer.
Once again taking up the book, the hero realizes that the Marquis de Rolbón was needed to him not to feel his existence. Thoughts about what he is, reduce Rokantena crazy. Now he lives only for the sake of meeting with Annie.
One day the hero dines with the Samouchka. For the first time in many years he has been talking to another person for so long. Samouchka admits that he is a socialist. Previously, he was also a loner, but in a concentration camp, in captivity, being trapped among people in a barn, he suddenly realized that he loved all of humanity. Samouchka tries to attract Rokanten to the humanistic side, but nothing comes of it. In the process of arguing, the protagonist almost plunges into the interlocutor fruit knife. Then he escapes from the cafe, sits on the tram and realizes that things have lost their names. In the park Rokanten comes to the idea that all existing objects interfere with each other, they, like him, are superfluous. The whole absurdity of life confronts the character in its entirety, and this is precisely Nausea.
In Paris, Rokanten meets with Annie. She has changed – has become stout, has ceased to search perfect moments and began to test fear of the world of things. She realized that everything and everything around her was the same, and she herself was a living dead man. The former lover has nothing more to say to each other. The next day, Annie leaves with another man in Egypt. Rokanten understands that he has nothing to live for.
He says goodbye to Bouville. In the library, he sees how Samoucha is sticking to the boys-lyceists. Listening for the last time in the cafe Françoise old record, the hero understands: you can go beyond the limits of existence through creativity, creating the Book of something “beautiful and hard as steel.”