Plot
Terry Lennox shows up at the Los Angeles apartment of his close friend, down-on-his-luck private eye Philip Marlowe, claiming he is in trouble and asking for a ride to Tijuana, Mexico. Returning from Tijuana, Marlowe learns that Terry's wife Sylvia was murdered. He is arrested on suspicion of being an accomplice, but soon released after Mexican authorities report that Terry has committed suicide in Mexico and admitted to killing his wife in a suicide note. Marlowe refuses to believe Terry was guilty.
Meanwhile, Eileen Wade hires Marlowe to find her missing husband, macho, alcoholic, and self-destructive novelist Roger Wade. Marlowe learns that the Wades were the Lennoxes' neighbors in Malibu Colony. He finds Roger at a rehab clinic and brings him home, but before they leave, the clinician, Dr. Verringer, demands payment for his services and vows to see Roger again.
Local gangster Marty Augustine and his henchmen rough Marlowe up at his apartment and demand that he help recover $355,000 that Terry was hired to deliver to Augustine's associates in Mexico City. Once they leave, Marlowe follows them to the Wades' house, where he sees Eileen and Augustine having a heated conversation. This leads him to conclude that the Wades are connected to the Lennoxes' deaths. He later learns that Roger owes Augustine a significant sum of money.
Marlowe travels to Mexico, but the Mexican police stick to their story. He returns to Malibu, where the Wades are hosting a party. Dr. Verringer crashes the party, once again demanding payment and slapping Roger. Although Roger drunkenly insults him, he pays Dr. Verringer and ends the party. Later that night, he walks into the ocean to commit suicide. Eileen and Marlowe rush into the water after him but cannot save him.
Hoping that Terry is still alive, Marlowe theorizes that Roger was having an affair with Sylvia and killed her to hide his infidelity, forcing Terry to flee the country. He badgers Eileen, who reluctantly confirms his theory. Marlowe asks the police to reopen the Lennox investigation; they dismiss his theory but confirm that Roger met with Sylvia before going to rehab.
Marlowe receives a goodbye letter from "Terry", with a rare $5,000 bill enclosed. Marlowe meets Augustine in his office, where upon discovering the bill, Augustine grows suspicious, noting that the money Terry was delivering included three such bills. Augustine threatens to cut Marlowe's genitalia off, but Terry's money arrives in the nick of time. Augustine lets Marlowe go and gives him the bill for his troubles. Outside, Marlowe glimpses Eileen driving away. He runs after her, but she does not acknowledge him, and he is hit by a car during the pursuit. Following a brief hospital stay, he finds that Eileen has sold her house and disappeared.
Marlowe returns to Mexico, where upon bribing local officials with the $5,000 bill, he learns that they were paid by a man with another $5,000 bill to fake Terry's suicide. Marlowe tracks Terry down at a Mexican villa. Terry explains that there was in fact an affair, but it was between him and Eileen. Roger discovered the affair and told Sylvia, who confronted Terry. Terry then killed Sylvia during a violent argument and fled. Terry gloats that no one cares about the case anymore since he is legally dead and Augustine got his money back. Marlowe asks Terry why he was framed as a suspect, but Terry dismissively calls him a "born loser". In response, Marlowe fatally shoots Terry.
As Marlowe walks away, he passes Eileen, who is driving to meet Terry. She is shocked to see him there, but continues on. Having obtained his revenge, Marlowe happily strolls down the road.
