The following version of this book was used to create the guide: Kleeman, Alexandra. Something New Under the Sun. Penguin Random House LLC., 2021.

Alexandra Kleeman's novel Something New Under the Sun is written from the third person point of view and in the present tense. Although the narrative form mutates and fragments over the course of the novel, the following summary adheres to a linear structure.

When middle-aged East Coast novelist Patrick Hamlin discovers that Hollywood producers want to adapt his novel Elison Lane to the screen, he is thrilled. Despite his wife Alison's concerns, Patrick readily decides to leave the East Coast for California to work on the production. Almost as soon as he arrives, however, he finds life in California disorienting and dislocating. Nothing is familiar to him, or feels exactly real.

Patrick feels even more unsettled when he encounters the movie script for the first time. The screenwriters have barely preserved the essence of his novel, and only the characters' names are recognizable to him. The story is important to Patrick, not only because he wrote it, but because it was inspired by his personal life. After his father's death, Patrick wanted to convey the ghostly experience of losing someone whose presence refuses to leave.

When Patrick meets Cassidy Carter, the actress chosen to play the female lead, he is skeptical. The other production assistants have told him about Cassidy, and he doubts she is right for the part. The producers, Jay and Brenda, tell Patrick that he should establish a relationship with Cassidy. They even task him with driving her to and from the studio on shoot days.

Cassidy proves moody and bratty, and Patrick has trouble reconciling with her behavior. He also feels frustrated that his role as writer is not being taken seriously. Whenever he feels overwhelmed, he gushes his feelings to Cassidy. Though she is confused by Patrick's behavior, Cassidy believes that his emotional displays are genuine.

Meanwhile, Alison takes her and Patrick's daughter, Nora, to a nature retreat called Earthbridge in upstate New York. Because Alison is constantly overcome by sorrow over the climate crisis, she believes the retreat will heal her. Patrick worries about them from California, convinced that Earthbridge is a cult.

A wildfire stalks the fringes of Hollywood, yet none of the characters pay attention to the threat it poses. Even when Patrick tries to focus on it, he cannot convince himself that the fire is a real emergency. He continues drinking WAT-R, a synthetic water-like beverage, in order to quench his perpetual dehydration.

Eventually, Patrick becomes suspicious of Jay and Brenda. He tells Cassidy that he thinks they are up to something nefarious. Because she is also frustrated with how Jay and Brenda are handling the production, she agrees to help him investigate the shady producers. They eventually discover that Jay and Brenda have no intentions of making the film, and are using the production as a front. Meanwhile, Patrick's disorientation worsens. He can barely maintain consciousness. Cassidy starts taking care of him, worried that he might be suffering from a WAT-R-induced illness called ROAD, or Random-Onset Acute Dementia.

When Alison learns about the wildfire, she is unable to focus on life at Earthbridge. She tries to get Patrick to fly home, but he is afraid that if he gets on the plane he will never return to the ground.

Patrick and Cassidy flee the worsening blaze in Hollywood. They end up in Joshua Tree, where Patrick's disorientation compels him to crawl for miles along the beach, hallucinating. Something similar soon happens to Cassidy.

Meanwhile, the world gradually dismantles itself, preparing itself for rebirth.