The main character in the novel Nausea is Antoine Roquentin, a historian who has retired to a small, depressing village called Bouville. The novel is made up of Roquentin’s journal entries from 1932, in which he records his ever-intensifying struggle to understand the sickening anguish that overwhelms him as he observes the world and questions its meaning.
Nausea begins with a fictional editors’ note, claiming that the diary was found in Roquentin’s papers, and the actual diary then begins with a brief introduction by Roquentin that explains his thoughts about diary keeping. In the entries that follow, Roquentin describes an uncomfortable feeling that plagues him from time to time—a feeling he calls “the Nausea.” He describes his daily life, in which he talks to few people, has casual sexual encounters with women, and thinks occasionally of a former lover named Anny. He interacts with the town and its people, often describing them and his interactions with them. He visits the library frequently and often sees and talks to someone he calls the Self-Taught Man. He wishes to escape the feelings of despair and hopelessness that overwhelm him, but he cannot repair the disconnect he feels with reason and the comforts of humanity. Failing to find salvation in his outward pursuits, he is forced to look inward, and he describes his confusion with what the world means and the Nausea that comes and goes.
In one entry, he reports receiving a letter from Anny, requesting that he meet her at a hotel. He remembers pieces of their past together and decides he’ll go to see her when she arrives in one week. In subsequent entries, he describes occasionally thinking about her as he goes about his daily life.
In conversation one day with the Self-Taught Man, Roquentin is suddenly struck by the reality of a dessert knife he is holding in his hand—the feel of the handle and blade, its appearance. Believing he suddenly understands the Nausea, he says, “Now I know: I exist—the world exists—and I know that the world exists.” He is overcome by the bare reality of existence. When he examines a stone on the seashore, the root of a chestnut tree, and other objects, he is taken aback by a revelation that exposes the things as pure existence rather than the “essence” of what they are. The discovery forces Roquentin to confront what he sees as the complete meaninglessness and nauseating purity of existence.
A few entries later, Roquentin describes his meeting with Anny, who looks older now. Their encounter is awkward, and Roquentin describes feeling uncomfortable in her hotel room. Although he is initially happy to see her, eventually the conversation becomes accusatory, with both of them bringing up hurts from the past. He dreads leaving her and knows he’ll probably never see her again. The next day, he finds her at the train station, but they do not speak, and her train leaves.
In an entry near the end of Nausea, Roquentin describes sitting in a café and spotting the Self-Taught Man at a table with two young boys. A Corsican sees the Self-Taught Man make a sexual advance to one of the boys, and he and another café patron say this isn’t the first time they’ve seen the Self-Taught Man do this kind of thing. The Corsican punches the Self-Taught Man in the face, and though Roquentin tries to help him, the Self-Taught Man orders him away.