L'histoire se déroule en 1981, à Gotham City. Arthur Fleck travaille dans une agence de clowns. Méprisé et incompris par ceux qui lui font face, il mène une morne vie en marge de la société et habite dans un immeuble miteux avec sa mère Penny. Un soir, il se fait agresser dans le métro par trois hommes alcoolisés qui le brutalisent, le poussant à les tuer en retour. Son geste inspire à une partie de la population l'idée de s'en prendre eux aussi aux puissants ; Arthur bascule peu à peu dans la folie et finit par devenir le Joker, un dangereux tueur psychopathe victime d'hallucinations.
A retired rock star, Johnny Boz, is stabbed to death with an ice pick during sex by a mysterious blonde woman at his apartment. Homicide detective Nick Curran investigates, and the only suspect is Catherine Tramell, Boz's bisexual girlfriend and a crime novelist who has written a novel that mirrors the crime. It is concluded that Catherine herself did it or someone who is trying to frame her out of spite. Tramell is uncooperative and taunting in the investigation, smoking in the interrogation room and exposing her bare genitalia in front of the officers. She presents alibis and passes a lie detector test. Nick discovers that Catherine has a habit of befriending murderers, including her girlfriend Roxy, who is later shown to have murdered several young boys on impulse, and Hazel Dobkins, who murdered her family.
Le célèbre détective belge Hercule Poirot prend l'Orient-Express pour rentrer d’Istanbul à Londres. Mais alors que le train se retrouve bloqué par la neige dans les montagnes yougoslaves, Samuel Ratchett, un riche Américain, est assassiné. À la demande de son ami M. Bouc, directeur de la ligne, Poirot se met à enquêter pour découvrir le meurtrier parmi les passagers.
Le romancier Harlan Thrombey convie dans son manoir sa famille, aussi excentrique que dysfonctionnelle, pour célébrer son 85e anniversaire. Mais le lendemain matin, le riche patriarche est retrouvé mort la gorge tranchée. Alors que tout indique un suicide, le détective privé Benoit Blanc s'invite dans l'enquête de l'inspecteur Elliott et commence à suspecter un meurtre.
Clarice Starling (Jodie Foster) is pulled from her training at the FBI Academy at Quantico, Virginia by Jack Crawford (Scott Glenn) of the Bureau's Behavioral Science Unit. He assigns her to interview Hannibal Lecter, a former psychiatrist and incarcerated cannibalistic serial killer, whose insight might prove useful in the pursuit of a serial killer nicknamed "Buffalo Bill", who skins his female victims' corpses.
An alcoholic air marshal named Bill Marks boards a Boeing 767 non-stop flight from New York City to London. He sits next to passenger Jen Summers with whom he engages in friendly conversations. After take-off, he receives a text message on his secure phone stating that someone will die every 20 minutes unless $150 million is transferred to a specific bank account. Marks breaks protocol and consults with Jack Hammond, the other air marshal, who concludes that the threat is not valid. Marks however consults the help of Summers and flight attendant Nancy to monitor the security cameras while texting the mysterious person in order to locate him. However, Hammond is texted by the unknown person who says that he knows what is in Hammond's briefcase. As Marks confronts Hammond in the rear lavatory, the latter is revealed to be smuggling cocaine in a brief-case. Hammond attacks Marks, who responds in self-defense and breaks Hammond's neck. This incident happens exactly at the 20-minute mark.
Rozat "Rusty" Sabich (Ford) is a prosecutor and the right-hand man of District Attorney Raymond Horgan (Dennehy). When his colleague, Carolyn Polhemus (Scacchi), is found raped and murdered in her apartment, Raymond insists that Rusty take charge of the investigation. The election for District Attorney is approaching and Tommy Molto (Joe Grifasi), the acting head of the homicide division, has left to join the rival campaign of Nico Della Guardia (Tom Mardirosian).
"Pumpkin" (Tim Roth) and "Honey Bunny" (Amanda Plummer) are having breakfast in a diner, and discussing their life as robbers. They decide to rob the restaurant after realizing they could make money off the customers as well as the business, as they did during their previous heist. Moments after they initiate the hold-up, the scene breaks off and the title credits roll.
The film opens with newsreel footage, including the farewell address in 1961 of outgoing President Dwight D. Eisenhower, warning about the build-up of the "military-industrial complex". This is followed by a summary of John F. Kennedy's years as president, emphasizing the events that, in Stone's thesis, would lead to his assassination. This builds to a reconstruction of the assassination on November 22, 1963. New Orleans District Attorney Jim Garrison subsequently learns about potential links to the assassination in New Orleans. Garrison and his team investigate several possible conspirators, including private pilot David Ferrie, but are forced to let them go after their investigation is publicly rebuked by the federal government. Kennedy's suspected assassin Lee Harvey Oswald is killed by Jack Ruby, and Garrison closes the investigation.
United States Secret Service Agents Frank Horrigan and Al D'Andrea meet with members of a counterfeiting group at a marina. The group's leader, Mendoza, tells Horrigan that he has identified D'Andrea as an undercover agent, and forces him to prove his loyalty by putting a gun to D'Andrea's head and pulling the trigger. Horrigan shoots Mendoza's men, identifies himself as an agent, and arrests the counterfeiter.
A joint mission of the American FBI and the Russian MVD leads to the death of the younger brother of an Azerbaijani mobster (David Hayman). In retaliation, the mobster hires an enigmatic assassin known only by the pseudonym "The Jackal" (Bruce Willis) to kill an unseen target. The Jackal demands $70 million for the job, to which the mobster reluctantly agrees. Meanwhile, the MVD capture one of the mafia's henchmen. During interrogation by torture, the henchman reveals the name "Jackal". This, coupled with the documents recovered from the henchman's briefcase, leads the FBI and MVD to assume the target for the retaliatory hit is FBI Director Donald Brown (John Cunningham).
In 1975, three children, Jimmy, Sean, and Dave, are playing on the streets of Boston when a stranger approaches them. Since the stranger has a badge and is wearing a suit, the children assume that he is a police officer. The stranger orders Dave to enter his car, and Dave obeys, but this leads to him being sexually abused and locked inside a basement for four days, after which he manages to escape.
U.S. President Henry Ashton (Hurt) attends a political summit in Salamanca, Spain, to promote an international treaty. Displayed with eight differing viewpoints, an assassination attempt on the president occurs, relayed in a time span of 23 minutes. Each time the events unfold from the beginning, a new vantage point is shown revealing additional details, which ultimately completes the story of what actually took place during the incident.
In the small fishing town of Nightmute, Alaska, 17-year-old Kay Connell (Crystal Lowe) is found murdered. LAPD detectives Will Dormer (Al Pacino) and Hap Eckhart (Martin Donovan) are sent to assist the local police with their investigation, at the request of police chief Nyback (Paul Dooley), an old colleague of Will's. Also, an intense Internal Affairs investigation in Los Angeles is about to put Dormer under the microscope. Eckhart reveals that Internal Affairs has offered him an immunity deal in exchange for his testimony regarding one of Dormer's past cases. Eckhart says that he has no choice but to accept the deal, to Dormer's frustration.
Corrupt, flamboyant Atlantic City police detective Rick Santoro (Nicolas Cage) attends a boxing match at Gilbert Powell's (John Heard) Atlantic City Arena between heavyweight champion Lincoln Tyler (Stan Shaw) and challenger Jose Pacifico Ruiz. He meets up with his best friend since childhood, Kevin Dunne (Gary Sinise), who is a US Navy Commander working with the Department of Defense to escort Defense Secretary Charles Kirkland (Joel Fabiani) and Powell at the fight after a trip to Norfolk, Virginia. As the first round begins, Dunne is distracted by an attractive redhead named Serena (Jayne Heitmeyer) who wears a ruby ring, and leaves his seat, which is then taken by Julia Costello (Carla Gugino), a mysterious woman with platinum blonde hair and a white satin suit.