Exposition (Initial Situation)
A Diary Might be a Good Idea
Sartre begins this novel by giving us a note from some fictional editors who have apparently prepared the diary of Antoine Roquentin for publication. They claim they have published the diary in its entirety without altering anything, and have even included a few undated pages that Antoine apparently wrote a few weeks before he started dating his journal entries.
Antoine's undated pages give us some insight into why he has decided to start writing a diary. Basically, he's concerned with the meaning of life, and he thinks that recording every little detail of his day-to-day life might reveal a larger pattern that will give significance to his existence. He also mentions that he is working on a history book to help give himself a sense of purpose. Overall, these early comments set up the main conflict that Antoine will struggle with for the rest of the novel, which stems from his profound doubts that life has any larger purpose or meaning.
Rising Action (Conflict, Complication)
You Just Can't Win
The harder Antoine tries to escape his feelings of meaninglessness, the deeper he sinks into despair and even madness. Everyday objects begin to feel as if they're surrounding him, his feelings of loneliness and boredom get worse by the day, and he becomes desperate to find some principle that will justify his existence. After his ex lover Anny turns him away for good, he realizes that there's nothing left to give him hope for finding meaning in the future. As things get worse, we sense that Antoine's struggles will eventually lead to either some kind of revelation or suicide.
Climax (Crisis, Turning Point)
The Truth of Existence
After a long conversation with the Self-Taught Man, Antoine rushes out of a restaurant and goes on a trippy, hallucination-filled walk through Bouville. During this walk, he looks at all the objects around him and realizes that:
Suddenly, suddenly, the veil is torn away, I have understood, I have seen. (21.299).
What Antoine sees is that human existence has no intrinsic meaning. People exist and then they don't, and the universe doesn't care whether they ever existed to begin with.
Usually, the climax of a novel leaves you feeling either satisfied or unsatisfied. But in Antoine's case, it kind of leaves us (and him) feeling both. As he tells us:
I can't say I feel relieved or satisfied; just the opposite, I am crushed. (25.1)
He realizes that he is a completely free individual who is responsible for his own actions, yet he has trouble feeling motivated to act in a universe that is totally indifferent to human life.
The Fall of the Self-Taught Man
As the novel winds to a close, Antoine decides to leave Bouville and visits the library one last time. When he's there, he sees his acquaintance, the Self-Taught Man, making sexual advances on a young boy. He rushes to the STM's rescue when the librarian punches the little man in the face, but the STM runs away from him as soon as they're outside the library. Some people might even consider this the actual climax of the book, but Antoine himself uses the word "climax" to describe his earlier realization about the truth of existence.
The fall of the Self-Taught Man shows us that the STM's philosophy of universal human love doesn't work so well in practice, because it leads the man to behave like a pedophile. Now that's not to say that thinking life is meaningless is a much better option. But then again, at least Antoine doesn't hit on high school boys.
Maybe I'll Write a Book
At the close of his diary, Antoine leaves Bouville to live in Paris. He decides that he would like to write a novel about something that has nothing to do with the question of existence. He doesn't think that doing this will make everything better. But he does believe that writing a novel will give some sort of shape to his past and make him feel like he's done something worthwhile with his life.
The decision is ironic, since Antoine begins the book with the decision to write a diary, and that project doesn't do much to make him feel better. We don't know whether writing a novel will make him feel better, either. But hey, at least he feels motivated to do something. To read more on the ending of the book, check out "What's Up With the Ending?"