Note: As there are two cuts of this movie, this plot description may be inaccurate.
Private detective Philip Marlowe (Humphrey Bogart) calls on new client General Sternwood (Charles Waldron) at his Los Angeles mansion. As he waits in the foyer, the General's younger daughter, Carmen (Martha Vickers), flirts seductively with Marlowe. Marlowe is indifferent towards her flirtatious comments, leaving Carmen intrigued. He is then led by Norris, the butler, into the sun room where he is introduced to the ailing but wealthy general, who wants to resolve gambling debts owed by Carmen to a bookseller named Arthur Gwynn Geiger. As Marlowe begins to leave, he is stopped by General Sternwood's oldest daughter, Mrs. Vivian Rutledge (Lauren Bacall), who questions Marlowe about what he is doing for her father. Vivian, who was recently divorced, suspects her father's true reason for calling in a detective is to find Sean Regan, his friend, companion and bodyguard who had mysteriously disappeared a month earlier. The general assumption, established as the film progresses, is that Regan has run off with a local gambler's wife, Mrs. Eddie Mars.
Marlowe goes to Arthur Geiger's rare book shop and quickly dons a disguise as he enters the shop under the premise of searching for several rare books. Agnes, the unfriendly shop assistant, claims that they don't have the book Marlowe is looking for, nor any of the other books he inquires about. Marlowe begins to suspect that the book store is a front. As he is talking with Agnes, a man enters the back room where Marlowe sees stacks of books and paper. His suspicions are correct: Geiger is illegally selling pornographic books. He asks to see Mr. Geiger, but Agnes claims that Geiger is not in. Marlowe leaves the store and takes shelter in a bookstore across the street as it begins to rain. While there, he asks the brunette bookstore clerk whether or not she has ever seen Geiger. She replies that she has. She describes Geiger as being in his early 40s, fat, with a Charlie Chan mustache and a glass eye. Marlowe and the attractive brunette begin to flirt. She removes her glasses and lets down her hair. Marlowe decides to wait for Geiger in the store. The clerk lowers the blinds and pulls out glasses for the bottle of rye Marlowe offers.
Marlowe and the clerk remain in the store, waiting for Geiger. Marlowe glimpses Geiger leaving his bookshop and bids goodbye to the clerk. Marlowe follows Geiger's to his home at La Verne Terrace. As Marlowe is getting out of his car, a second car pulls up to the front of the house. A woman gets out and runs inside. Marlowe checks the registration on the car that pulled up, it reads "Carmen Sternwood". Marlowe goes back to wait in his car. Time passes. He sees a flash of light, then hears a gunshot and a scream, immediately followed by the quick getaway of two of the cars parked behind the house. Marlowe enters Geiger's house, where he finds Geiger's dead body on the living room floor. Next to it he finds Carmen, high and wearing an Asian dress, a subtle indication that she had somehow been modeling for Geiger's pornography books. Marlowe looks around the room and finds a statue with a camera hidden inside of it. The camera's film cartridge is empty. Marlowe leaves the scene and returns Carmen to her home, where he tricks Vivian into revealing that Carmen had a connection with Sean Reagan.
Marlowe walks back to Geiger's house to retrieve his car. Inside, Geiger's corpse is nowhere to be found.
Back in his office, Marlowe receives a phone call from Bernie Ohls, Chief Inspector of Homicide, who works for the District Attorney. Ohls and Marlowe are friends from when Marlowe worked for the DA. Bernie tells Marlowe that a car registered to the Sternwoods has been found off the Lido Pier. After arriving at the scene, Bernie questions Marlowe about his work for the Sternwoods and urges him to let go of the case. They discover that the driver of the car was Owen Taylor, the Sternwood's chauffer who was in love with Carmen. Owen Taylor has been blackjacked then pushed into the ocean in his car.
The next morning, Vivian comes to Marlowe's office. She has been sent a scandalous picture of Carmen and a blackmail demand for the negatives from Agnes. Vivian says she can get the money from Eddie Mars (Joe Ridgley). She is supposed to make the drop that evening. She promises to call Marlowe to let him know where the drop will be made. Marlowe returns to Geiger's bookshop, and discovers that they are packing up the store. Marlowe follows the car leaving Geiger's store in a taxi and arrives at 405 Randall Arms, the apartment of Joe Brody (Louis Jean Heydt). Joe Brody is a gambler who has previously blackmailed General Sternwood for $5,000.
Marlowe returns to Geiger's house where he finds Carmen attempting to get inside. She initially claims to know little about the murder of Geiger but then claims Brody killed Geiger. They are then surprised by someone unlocking the front door. The man is the owner of the home, who Marlowe realizes is Eddie Mars. Marlowe and Mars share a brief conversation, where Marlowe claims that he is there working for Carmen. The two are looking for Geiger, who he claims gave Carmen "the loop." Mars tries to bully Marlowe into telling him who cleaned out Geiger's store.
Evening comes. Vivian calls to say that she hasn't heard anything from the blackmailer. On a hunch, Marlowe drives to Joe Brody's apartment and waits outside. Vivian drives up and enters the apartment. Marlowe uses his knowledge of Geiger to force his way in. Joe Brody, Agnes (Geiger's assistant) and Vivian are inside. Marlowe accuses Joe Brody of murdering Owen Taylor for the photos. He also says that Brody can be framed for Geiger's killing. Marlowe demands the film. The door buzzes and Brody opens it to be greeted at gunpoint by Carmen, who has come for her pictures. Marlowe takes the film from Brody and sends Vivian and Carmen home. After the women leave, Brody admits he was blackmailing both Colonel Sternwood and Vivian. He professes innocence for both murders, however. Joe Brody says that he was waiting in his car in back of Geiger's house the night that Geiger was shot, but that there was another car down the hill (presumably Owen Taylor). Brody confesses to taking the film off of Owen Taylor and blackjacking him.
There is another knock at the door and, as Brody opens it, he is shot and killed; the assailant runs down the stairs to escape. Marlowe follows and apprehends him, only to find that he is Carol Lundgren, Geiger's "shadow", who has killed Brody in revenge, falsely believing that Brody was Geiger's killer. Marlowe brings Lundgren back to Geiger's house. Marlowe ties up Lundgren and calls Detective Bernie Ohls to come pick him up
With Geiger's murder attributed to Owen Taylor, Owen Taylor's likely killer (Brody) now dead himself, and Lundgren turned in to the police for the Brody killing, Vivian Sternwood is anxious for Marlowe to close the case. Marlowe, however, is worried about a number of unanswered questions revolving around Eddie Mars and Regan. He refuses to be "sugared off" the case. Their conversation is highly sexually charged, exposing a romantic tension that has been building throughout the film.
Marlowe visits Mars' casino, where he finds Vivian singing. He asks Mars about Regan, who is supposed to have run off with Mars' wife, but Mars is evasive. He tells Marlowe that Vivian is leaving bad IOUs in his casino.
Vivian wins a great amount of money at the tables and wants Marlowe to drive her home. He waits in his car for her, then foils Mars' thugs attempting to rob Vivian of her winnings. But Marlowe realizes the attempted robbery was faked and presses Vivian on her association with Mars. As he unsuccessfully questions her, they kiss.
Marlowe returns home to find Carmen waiting for him. He asks her about Regan and she admits she didn't like him. She also mentions that Mars calls Vivian frequently.
In the morning, Detective Bernie Ohis calls Marlowe and tells him to lay off the Sternwood case. Marlowe suspects the key to the mystery is Mars and Regan and persuades Ohis to back off. Marlowe then calls the Sternwood mansion and Vivian tells him Regan has been found in Mexico.
Marlowe is then brutally beaten by two of Mars' thugs, who tell him to lay off the case. He is helped by Harry Jones (Elisha Cook, Jr.), an associate of Brody's. Jones conveys an offer from Agnes to reveal the location of Mars' wife for $200. However, when Marlowe goes to meet him, Canino, a hired killer of Mars', has gotten there first. He gets Agnes' location from Jones before poisoning him. It turns out to have been a false location. When Agnes tries to call Jones, Marlowe arranges a meeting with her.
Agnes tells Marlowe that she's seen Eddie Mars' wife near Realito by a "car drop" called Art Huck's Car Repair. This is a location where Eddie Mars repaints stolen cars.
Marlowe follows her tip and fakes a flat tire to gain entry to the Art Huck's Car Repair shop. But he is attacked and knocked out by Canino. He wakes to find himself locked up with Mars' wife, who has no idea where Regan is. Vivian is also hiding there. Mona Mars believes her husband is innocent of any killings and leaves when Marlowe tells her about Jones' death. Vivian, fearing for his life, kisses and frees Marlowe. When Canino arrives, Marlowe gets to his car and his gun. He eventually is able to kill Canino with Vivian's help.
Marlowe and Vivian drive back to Geiger's apartment. She says, "what if I told you I killed Sean Regan", but Marlowe does not believe her. When they arrive at Geiger's house, Marlowe calls Eddie Mars. Marlowe says that he is still in Realito at the payphone. They arrange to meet at Geiger's house, giving Marlowe ten minutes at the house before Mars will arrive. Marlowe says, " Mars has been ahead of me all the way, if I don't get him this time, we're cooked." When Mars arrives to set up an ambush, Marlowe surprises him and holds him at gunpoint. Mars admits that it was Carmen that killed Regan after being spurned. Mars covered it up but was blackmailing Vivian.
Marlowe wounds Mars and he runs out. But his men, waiting to ambush Marlowe, shoot and kill Mars. Marlowe calls Bernie Ohls to wrap up the case but tells him that Mars killed Regan. Marlowe and Vivian decide to commit Carmen and conceal the truth from the dying Colonel Sternwood. They wait in the dark as sirens approach, now committed to each other.
This version of The Big Sleep is remembered for its convoluted plot. Famous gossip is that during filming neither the director nor the screenwriters knew who killed chauffeur Owen Taylor or if he had killed himself. They sent a cable to Chandler who told this to a friend in a letter: "They sent me a wire... asking me, and dammit I didn't know either".
After its completion, Warner Bros. did not release The Big Sleep until they had released a backlog of war-related films, because the war was ending and the public might find them uninteresting, whereas The Big Sleep's subject was not time-sensitive. Attentive observers will note indications of the film's war-time production, such as ration stamps, period dialogue, pictures of President Franklin D. Roosevelt, and a woman taxi driver who says to Bogart: "I'm your girl."
The "Bogie and Bacall" phenomenon, which had begun with To Have and Have Not and their marriage, was in full swing by the end of the war and Bacall's agent asked that portions of the film be re-shot to capitalize on her new celebrity. Producer Jack Warner agreed, and new scenes were added, such as the sexually suggestive race horse dialogue scene. The re-shot ending featured Peggy Knudsen as "Mona Mars" because Pat Clark, the originally-cast actress, was unavailable. Consequently, because of the two versions created by the re-shooting, there is a substantial content difference of some twenty minutes between them, although the running time difference between the two versions is two minutes. The re-shot, revised version of The Big Sleep was released on 23 August 1946.
The cinematic release of The Big Sleep is regarded as more successful than the pre-release version (see below), although it is confusing and difficult to follow. For example, it omits a long conversation between Marlowe and the Los Angeles District Attorney where facts of the case, thus far, are exposited. Yet movie star aficionados prefer it to the film noir version because they consider the Bogart-Bacall appearances more important than a well-told story. For an example of this point of view, see Roger Ebert's "Great Movies" essay on the film.
Although Martha Vickers plays Lauren Bacall's younger sister, she was only eight months her junior.
The Big Sleep was made in the age of Hays Office censorship, when it was expected that adults would understand certain story points that would be lost to children. In the novel, the books Geiger profitably rents are pornography, then illegal and associated with organized crime. The photograph of Carmen wearing a "Chinese dress" and sitting in a "Chinese chair" alludes to that.
In the film, Joe Brody is killed by Carol Lundgren who believes he killed Geiger. In the novel, Lundgren is Geiger's homosexual lover, a detail which goes unmentioned in the film.
In the novel, Marlowe finds pornographic photographs of Carmen and later finds her naked in his bed. In the film, the photographs show Carmen was at Geiger's house when he was killed (thus possibly implicating her in his murder). The novel's nude bedroom scene in Marlowe's apartment is altered in the film to a clothed Carmen awaiting him in an armchair.
The authorised DVD is a double-sided, single-layer disc; the 1945 film noir version is in side-A, the 1946 movie star version is in side-B.
The Washington Post Critics Corner calls the film "an unqualified masterpiece."
Although the film's reception was overwhelmingly positive a number of critics, whilst commending the performance of the leading actors have criticised the film for its convoluted and difficult to follow plot. Carlo Cavagna said of the film: "Bogart and Bacall are so good together that the story's impenetrability doesn't matter much."