In 1996, treasure hunter Brock Lovett and his team aboard the research vessel Akademik Mstislav Keldysh search the wreck of RMS Titanic for a necklace with a rare diamond, the Heart of the Ocean. They recover a safe containing a drawing of a young woman wearing only the necklace dated April 14, 1912, the day the ship struck the iceberg. Rose Dawson Calvert, the woman in the drawing, is brought aboard Keldysh and tells Lovett of her experiences aboard Titanic.
Two years after the events of the previous film, Larry Daley (Ben Stiller) is now CEO of Daley Devices, a direct response television company that sells inventions inspired by his experiences as a night security guard at the American Museum of Natural History. While wealthy and successful, he has not had the time to see his museum exhibit friends in several months.
As a child, Colin Sullivan (Damon) had been introduced to organized crime by Irish-American mobster Frank Costello (Nicholson) in the Irish neighborhood of South Boston. Over the years, Costello grooms him to become a mole inside the Massachusetts State Police, until Sullivan is accepted into the Special Investigations Unit, which focuses on organized crime.
In 2154, Earth is overpopulated and polluted. Most of the earth's citizens live in poverty, on the edge of starvation, and with little technology and medical care. The rich and powerful live on Elysium — a gigantic, terraformed space habitat located in Earth's orbit. Elysium is technologically advanced; such technology includes Med-Bays: medical machines that can cure all diseases, reverse the aging process and regenerate new body parts. A long-running feud exists between the wealthy residents of Elysium and the citizens of Earth, who want Elysian technology to cure their medical ailments.
Lorna Cole (Rene Russo) is pregnant with LAPD sergeant Martin Riggs' baby; they are not married, but both are thinking about it. Police sergeant Roger Murtaugh's daughter Rianne (Tracie Wolfe), is also pregnant, and Riggs later learns from Lorna that Rianne has secretly married Lee Butters (Chris Rock), a young detective who works at the same station as Murtaugh and Riggs – secretly because Roger had made it clear that he does not want his daughter to marry a police officer. Due to the many disasters caused by both sergeants while on duty, the police department has lost its insurance carrier, and cannot get a new one while they're still out on the streets. Because firing them is not an option, the Chief uses a special privilege and they get temporarily promoted to captains, given that there aren't any lieutenant spots available.
On the occasion of his daughter Connie's wedding, Vito Corleone hears requests in his role as the Godfather, the Don of a New York crime family. Vito's youngest son, Michael, wearing a Marine Corps uniform, introduces his girlfriend, Kay Adams, to his family at the reception. Johnny Fontane, a famous singer and godson to Vito, seeks his help in securing a movie role; Vito dispatches his consigliere, Tom Hagen, to Los Angeles to talk the abrasive studio head, Jack Woltz, into giving Johnny the part. Woltz is unmoved until he wakes up in bed with the severed head of his prized stallion.
Viktor Navorski (Tom Hanks), a traveler from the nation of Krakozhia, arrives at New York's John F. Kennedy International Airport, only to find that his passport is suddenly no longer valid due to the outbreak of a civil war in his homeland. As a result, the United States no longer recognizes Krakozhia as a sovereign nation, and he is not permitted to either enter the country or return home as he is now stateless. Due to his inability to communicate in proper English, US Customs and Border Protection seizes his passport and airline ticket.
In an alternate 1982, an alien ship inexplicably stops over Johannesburg. When investigation teams enter the ship, they discover a population of sick and malnourished extraterrestrials, derogatorily referred to as "prawns". The South African government confines the aliens to "District 9", a government camp that is located outside of Johannesburg. Twenty-eight years later, in 2010, following periodic conflict between the aliens and the locals living near District 9, the government hires private military company Multinational United (MNU) to relocate the aliens to a new internment. Wikus van de Merwe (Sharlto Copley), an Afrikaner bureaucrat, is appointed by Piet Smit (Louis Minnaar), an MNU executive and his father-in-law, to lead the relocation.
On February 6, 1846, at Paradise Square in Lower Manhattan's Five Points, a territorial battle of hand-to-hand combat between Bill "the Butcher" Cutting's U.S.-born nativist gang, the Natives, and "Priest" Vallon's Irish Catholic immigrant gang, the Dead Rabbits, concludes when Cutting kills Vallon, witnessed by Vallon's young son, Amsterdam. Cutting declares the Dead Rabbits outlawed but orders that Vallon's body be buried with honor. Amsterdam seizes the knife used to kill his father, races off, and buries it along with a medal his father gave him. He is later raised at Hellgate orphanage.
Claude Verneuil, a Gaullist notary, and his wife Marie, a Catholic bourgeois from Chinon, are parents of four daughters: Isabelle, Odile, Ségolène, and Laure. The three eldest are already married to men, each one of a different religion and a different 'ethnic' origin: Isabelle married Rashid Ben Assem, a Muslim Arab, Odile married David Benichou, a Sephardi Jew, and Ségolène married Chao Ling, a Chinese man. The Verneuils pretend to accept their sons-in-laws but have had a hard time hiding their comfortability in accepting people into the family from outside the community. A family meeting is spoiled because of the awkwardness and clichés about race and religion, stated as much by the father as by the sons-in-laws who even exchange insulting communitarist views to and about each other.
In 1979, as Michael Corleone is approaching 60, he regrets his ruthless rise to power, and is especially guilt-ridden for having his brother, Fredo, murdered. He has semi-retired from the Mafia, leaving the Corleone family's criminal interests under enforcer Joey Zasa's control. Michael uses his tremendous wealth and power in an attempt to rehabilitate his reputation via numerous charitable acts. Michael and Kay divorced in 1960, and Kay was given custody of their children, Anthony and Mary.
Aging gangster Benjamin "Lefty" Ruggiero is introduced to a jewel thief named Donnie Brasco. Donnie impresses Lefty by threatening a diamond dealer Donnie suspects of selling Lefty a fake ring. Lefty teaches Donnie the rules of the Mafia and introduces him to several "made men" including Dominick "Sonny Black" Napolitano, and Nicholas Santora, as well as caporegime Alphonse “Sonny Red” Indelicato to whom Lefty owes money and is disliked by Sonny Black.
In 1973, Sam "Ace" Rothstein (Robert De Niro) is a sports handicapper and Mafia associate who is sent to Las Vegas to run the Teamsters Union-funded Tangiers Casino on behalf of the Chicago Outfit. He hires old friend Billy Sherbert (Don Rickles) as his manager. In between, Ace and his friend, mob enforcer and caporegime Nicholas "Nicky" Santoro (Joe Pesci), narrate how the mob bosses control the Teamsters Union, which gives out money for casinos that they own, such as The Tangiers, and how they also drive off rival crews and get rid of cheaters. Ace becomes the Tangiers' de facto boss by taking advantage of lax gaming laws allowing him to work at the casino while his gaming license is still pending. He doubles the casino's profits, which are skimmed by the Mob before the records are reported to income tax agencies. The bosses are impressed with Ace's work and send Nicky to protect Ace and the whole business, along with Nicky's brother Dominick, Nicky's friend and subordinate Frank Marino (Frank Vincent), and the rest of Nicky's soldiers in his crew. Nicky, however, becomes more of a liability than an asset; his criminal activities- which he makes nearly no effort to conceal- and his violent and vicious temper quickly gets him banned by the gaming board from every casino, and his name is placed in the Black Book. In retaliation, Nicky gathers his own crew, opens a jewelry store and restaurant, begins running unsanctioned shakedowns and burglaries, and soon after is considered the mob boss of Vegas.
In 1901, Corleone, Sicily, nine-year-old Vito Andolini’s family is killed after his father insults local Mafia chieftain Don Ciccio. He escapes to New York and is registered as "Vito Corleone" on Ellis Island.
In 1975, James "Whitey" Bulger (Johnny Depp), leader of the Irish-American Winter Hill Gang, controls almost all of organized crime within South Boston, along with his right-hand man Stephen Flemmi (Rory Cochrane), newcomer Kevin Weeks (Jesse Plemons), and cold and calculative hitman, Johnny Martorano (W. Earl Brown). Bulger's hold over South Boston is challenged by the northern Angiulo Brothers, who head the Boston branch of the New England Mafia family.