The Sternwood Summons
Private detective Philip Marlowe arrives at the Sternwood mansion in Los Angeles, a grand but aging estate. He meets General Sternwood, a rich, wheelchair-bound man who hires him to investigate a blackmail scheme against his youngest daughter, Carmen. The blackmailer is Arthur Geiger, a rare book dealer. During their talk, Marlowe also meets Vivian Sternwood Regan, the General's older, more refined daughter, who seems to know more than she says. The General mentions his concern about Rusty Regan, Vivian's husband and his favorite son-in-law, who disappeared months ago.
Geiger's Bookstore and a Murder
Marlowe begins his investigation by watching Arthur Geiger's rare book shop, which he soon realizes is a front for an illegal pornography ring. He follows one of Geiger's employees, Carol Lundgren, to Geiger's house. Later that night, Marlowe returns to Geiger's house and sees Carmen Sternwood go inside. Soon after, he hears gunshots and screams. Marlowe breaks in to find Geiger dead, shot, and Carmen drugged and naked, standing over the body. Before the police arrive, Marlowe helps Carmen escape and takes a camera from the scene, suspecting a blackmail photo scheme.
The Missing Body and the Blackmail Photos
Marlowe returns to Geiger's house the next morning, but the body is gone. He meets Captain Ohls of the Missing Persons Bureau, who is investigating Rusty Regan's disappearance, and Bernie Ohls, a district attorney investigator. Marlowe searches Geiger's house and finds a hidden safe with the blackmail negatives involving Carmen. He takes them. Soon after, Lundgren, Geiger's lover, appears, upset about Geiger's death. Marlowe realizes that Lundgren likely moved the body and seeks revenge for Geiger's murder, which he wrongly blames on Marlowe.
Joe Brody and Agnes Lowzier
Marlowe traces the blackmail photos to Joe Brody, a small-time criminal who had worked with Geiger. He confronts Brody, who is now trying to blackmail Vivian Sternwood Regan with the same photos of Carmen. Vivian is at Brody's apartment when Marlowe arrives. During their tense conversation, Agnes Lowzier, Geiger's former cashier and Brody's current girlfriend, enters. She is a tough, cynical woman who knows a lot about the criminal underworld. Marlowe gets the photos from Brody, but the situation remains tense, with several people wanting the evidence.
The Death of Joe Brody
As Marlowe leaves Brody's apartment, he notices a car following him. He returns to Brody's building and finds Brody dead in the hallway, shot. Marlowe hides and soon sees Carol Lundgren running away. Marlowe catches Lundgren, who admits to killing Brody, believing Brody had killed Geiger. Marlowe, understanding Lundgren's grief-driven reason and knowing Brody was not Geiger's killer, does not turn him over to the police immediately. Instead, he helps Lundgren disappear, seeing the complex nature of justice in this corrupt world.
Eddie Mars and the Gambling Den
Marlowe's investigation leads him to Eddie Mars, a well-known gambler and owner of The Cypress Club casino. Mars's wife, Mona Mars, had supposedly run off with Rusty Regan, Vivian's missing husband. Marlowe visits The Cypress Club, where he observes Mars and his operations. He also encounters Vivian, who is a regular at the club and seems to have a complicated relationship with Mars. Marlowe suspects Mars is involved in more than just gambling and that the disappearance of Mona and Regan is part of a larger plan, possibly connected to the blackmail and murders.
Carmen's Attempted Murder
Marlowe receives a call from Carmen Sternwood, who asks him to come to her room. When he arrives, she is very agitated. She propositions Marlowe, and when he rejects her, she pulls a small gun and tries to shoot him. Marlowe disarms her, realizing how unstable she is and how violent she can be. This event shows Carmen's dangerous and unpredictable nature, suggesting she might be capable of more serious crimes, and complicates Marlowe's efforts to protect the Sternwood family.
The Oil Well and the Missing Car
Following a hunch and some clues, Marlowe drives to the Sternwood oil fields, a remote part of the family's property. He finds an abandoned car submerged in an oil sump. Inside the car, he discovers a skeleton, confirming his suspicions about Rusty Regan's fate. The car belongs to Owen Taylor, the Sternwood's chauffeur who had also disappeared around the same time as Rusty Regan. This discovery solves the long-standing mystery of Regan's disappearance and links it directly to the Sternwood estate.
The Truth About Rusty Regan
Marlowe confronts Vivian with the evidence from the oil well. Under pressure, Vivian finally confesses the truth about Rusty Regan's death. She reveals that Carmen, in one of her psychotic rages, had shot and killed Rusty Regan because he rejected her. Vivian, to protect her sister and the family name, and with Eddie Mars's help, had covered up the murder, putting Regan's body in the oil sump and framing Owen Taylor for the disappearance, making it look as if Taylor had run off with Mona Mars.
The Final Confrontation with Eddie Mars
Marlowe confronts Eddie Mars, who tries to bribe him into silence. Mars, a master manipulator, had used the disappearance of Mona Mars and Rusty Regan to extort money from Vivian and to control her. Marlowe refuses to be bought. Mars's men try to kill Marlowe, leading to a tense shootout at a remote garage where Marlowe is ambushed. Marlowe outsmarts and outshoots his attackers, escaping with his life, but several of Mars's thugs are killed. This final encounter confirms Mars as the main antagonist behind much of the book's chaos.
The Loose Ends and the Big Sleep
With the truth about Rusty Regan's death out and Eddie Mars's operation broken up, Marlowe finishes the remaining tasks. He ensures that Carmen is institutionalized for her own safety and the safety of others. Vivian is left to deal with the aftermath of her family's dark secrets. Marlowe thinks about the widespread corruption he has found and the morally unclear nature of justice. He considers the meaning of 'the big sleep,' a term for death, understanding that many characters in the story have found their own version of it, literally or figuratively, in Los Angeles.