Henry Hill says, "As far back as I can remember, I always wanted to be a gangster", referring to his idolizing the Lucchese crime family gangsters in his blue-collar, predominantly Italian-American neighborhood in East New York, Brooklyn. Wanting to be part of something significant, Henry quits school and goes to work for them. He is able to make a living for himself and learns the two most important lessons in life: "Never rat on your friends, and always keep your mouth shut", the advice given to him after being acquitted of criminal charges early in his career.
A wealthy executive named Kingo Gondo (Toshiro Mifune) is in a struggle to gain control of a company called National Shoes. One faction wants the company to make cheap, low quality shoes for the impulse market as opposed to the sturdy but unfashionable shoes currently being produced. Gondo believes that the long-term future of the company will be best served by well made shoes with modern styling, though this plan is unpopular because it means lower profits in the short term. He has secretly set up a leveraged buyout to gain control of the company, mortgaging all he has.
After a rooftop chase, where his acrophobia and vertigo result in the death of a policeman, San Francisco detective John "Scottie" Ferguson retires. Scottie tries to conquer his fear, but his friend and ex-fiancée Midge Wood suggests another severe emotional shock may be the only cure.
Walter Neff (Fred MacMurray), a successful insurance salesman, returns to his office building in downtown Los Angeles late one night. Visibly in pain, he begins dictating a confession into a Dictaphone for his friend and colleague, Barton Keyes (Edward G. Robinson), a brilliant claims adjuster. The story, told primarily in flashback, ensues.
A group of children are playing an elimination game in the courtyard of an apartment building in Berlin using a chant about a murderer of children. A woman sets the table for dinner, waiting for her daughter to come home from school. A wanted poster warns of a serial killer preying on children, as anxious parents wait outside a school.
In early 1950s Los Angeles, Detective Sergeant Edmund "Ed" Exley (Guy Pearce), the son of a legendary LAPD detective, is determined to live up to his father's reputation. His intelligence, insistence on following regulations and cold demeanor contribute to his isolation from other officers. He exacerbates this resentment by volunteering to testify in a police brutality case, insisting on a promotion to Detective Lieutenant against the advice of Captain Dudley Smith (James Cromwell). Exley's ambition is fueled by the murder of his father by an unknown assailant, to whom he refers as "Rollo Tomasi" to give him personality.
Mob-connected union boss Johnny Friendly (Lee J. Cobb) gloats about his iron-fisted control of the waterfront. The police and the Waterfront Crime Commission know that Friendly is behind a number of murders, but witnesses play "D and D" ("deaf and dumb"), accepting their subservient position rather than risking the danger and shame of informing.
American pulp Western writer Holly Martins (Joseph Cotten) arrives in Allied-occupied Vienna seeking his childhood friend, Harry Lime (Orson Welles), who has offered him a job. Upon arrival he discovers that Lime was killed just days earlier by a speeding truck while crossing the street. Martins attends Lime's funeral, where he meets two British Army Police: Sergeant Paine (Bernard Lee), a fan of Martins' pulp fiction; and his superior, Major Calloway (Trevor Howard), who says Lime was a criminal and suggests Martins leave town.
A woman identifying herself as Evelyn Mulwray (Ladd) hires private investigator J. J. "Jake" Gittes (Nicholson) to carry out surveillance on her husband, Hollis I. Mulwray (Zwerling), chief engineer for the Los Angeles Department of Water and Power. Gittes tails him, hears him publicly oppose the creation of a new reservoir, and shoots photographs of him with a young woman (Palmer), which are published on the front page of the following day's paper. Upon his return to his office, Gittes is confronted by a beautiful woman who, after establishing that the two of them have never met, irately informs him she is the real Evelyn Mulwray (Dunaway) and that he can expect a lawsuit.
Tony "le Stéphanois" has served a five-year prison term for a jewel heist and is out on the street and down on his luck. His friend Jo approaches him about a smash-and-grab proposed by mutual friend Mario in which the threesome would cut the glass on a Parisian jeweler's front window in broad daylight and snatch some gems. Tony declines. He then learns that his old girlfriend, Mado, took up in his absence with gangster Parisian nightclub owner Pierre Grutter. Finding Mado working at Grutter's, Tony invites her back to his rundown flat. She is obviously well-kept, and Tony savagely beats her for being so deeply involved with Grutter. Tony changes his mind about the heist; he now accepts on the condition that they rob the jeweler's safe instead of the window. Mario suggests they employ the services of Italian compatriot César, a safecracker. The four devise and rehearse an ingenious plan to break into the store and disarm its sophisticated alarm system.
Chuck Tatum is a fiercely ambitious, self-centered, wisecracking, down-on-his-luck reporter who has worked his way down the ladder. He has come west to New Mexico from New York City, along the way being fired from eleven newspapers for libel, adultery, and heavy drinking, among other charges. Now that his car has broken down and Tatum is broke, he talks his way into a reporting job for the Albuquerque Sun-Bulletin, a paper of little consequence.
Arthur "Cody" Jarrett (James Cagney) is a ruthless, deranged criminal gang leader. Although married to Verna (Virginia Mayo), Cody is overly attached to his equally crooked and determined mother, "Ma" Jarrett (Margaret Wycherly), his only real confidante (Cody's father died in an insane asylum). Cody suffers from debilitating headaches, and Ma consoles him--even sitting him on her lap and giving him a shot of whiskey with the toast, "Top of the world," an expression she uses more than once.
Asmaa (Hend Sabry) is a woman in her 40s living with her aging father Hosni (Sayed Ragab) and teenage daughter Habiba (Fatma Adel) in Cairo, and struggling to support them with her meagre earnings from a menial job at Cairo International Airport. She is HIV-positive and requires surgery on her gallbladder, without which she will die. Doctors refuse her surgery when, on the point of entering the operating theatre, she reveals that she has AIDS.
In the 1930s West Virginia, along the Ohio River, Reverend Harry Powell, a serial killer, flees the scene of his latest victim. Powell is a self-anointed preacher with a penchant for switchblade knives; a misogynist who is both attracted to and repulsed by women. He travels rural roads, preaching in small towns, and seems to believe he is doing God's work. The letters "L-O-V-E" are tattooed on one hand and the letters "H-A-T-E" on the other, which Powell uses as symbols in impromptu sermons. In one small town, police arrest Powell for driving a stolen car and sentence him to jail, unaware that he is a murderer.