The film begins at Sannomiya Station on 21 September 1945, shortly after the end of World War II. A boy, Seita (清太), is shown dying of starvation. Later that night, having removed Seita's body, a janitor digs through his possessions and finds a candy tin which he throws away into a nearby field. The spirit of Seita's younger sister, Setsuko (節子), springs from the tin and is joined by Seita's spirit as well as a cloud of fireflies. Seita's spirit then begins to narrate their story accompanied by an extended flashback of the final months of World War II.
In Rome, in the 1980s, famous Italian film director Salvatore Di Vita returns home late one evening, where his girlfriend sleepily tells him that his mother called to say someone named Alfredo has died. Salvatore obviously shies from committed relationships and has not been to his home village of Giancaldo, Sicily in 30 years. As his girlfriend asks him who Alfredo is, Salvatore flashes back to his childhood.
In September 1939, Władysław Szpilman (Adrien Brody), a Polish-Jewish pianist, is playing live on the radio in Warsaw when the station is bombed during Nazi Germany's invasion of Poland which caused the outbreak of World War II. Hoping for a quick victory, Szpilman celebrates with his posh family at home when learning that Britain and France have declared war on Germany. German troops soon enter Warsaw and the Nazi authorities implement measures to identify, isolate, financially ruin and reduce the Jewish population in Warsaw. Jews are ordered to provide their own identifying armbands with the Star of David.
After breaking his leg photographing a racetrack accident, professional photographer L. B. "Jeff" Jefferies (James Stewart) is confined to his Greenwich Village apartment, using a wheelchair while he recuperates. His rear window looks out onto a small courtyard and several other apartments. During a summer heat wave, he passes the time by watching his neighbors, who keep their windows open to stay cool. The tenants he can see include a dancer he nicknames "Miss Torso", a lonely woman he nicknames "Miss Lonelyhearts", a composer-pianist, several married couples, a middle-aged sculptor, and Lars Thorwald (Raymond Burr), a traveling jewelry salesman with a bedridden wife.
During a lunchtime tryst in Phoenix, Arizona, a real estate secretary named Marion Crane discusses with her boyfriend, Sam Loomis, how they cannot afford to get married because of Sam's debts. After lunch, Marion returns to work, where a client drops off a $40,000 cash payment on a property. Her boss asks her to deposit the money in the bank, and she asks if she can take the rest of the afternoon off. Returning home, she begins to pack for an unplanned trip, deciding to steal the money and give it to Sam in Fairvale, California. She is seen by her boss on her way out of town, which makes her nervous. During the trip, she pulls over on the side of the road and falls asleep, only to be awakened by a state patrol officer. He is suspicious about her nervous behavior but allows her to drive on. Shaken by the encounter, Marion stops at an automobile dealership and trades in her Ford Mainline, with its Arizona license plates, for a Ford Custom 300 that has California tags. Her transaction is all for naught - the highway patrolman sees her at the car dealership and witnesses her purchase of the newer car.
Andrew Neiman is a first-year jazz student at the prestigious Shaffer Conservatory in New York. He has been playing drums from a young age and aspires to become one of the greats like Buddy Rich. Famed conductor Terence Fletcher discovers Andrew practicing in the music room late one night and eventually invites him into his studio band as the alternative for core drummer Carl Tanner. Fletcher is abusive toward his students, mocking and insulting them; when the band rehearses the Hank Levy piece "Whiplash" and Andrew struggles to keep his tempo, Fletcher hurls a chair at him, slaps him, and berates him in front of the class.
The film portrays two conflicts that take place around Flagstone, a fictional town in the American Old West: a land battle related to construction of a railroad, and a mission of vengeance against a cold-blooded killer. A struggle exists for Sweetwater, a piece of land near Flagstone containing the region's only water source. The land was bought by Brett McBain (Frank Wolff), who foresaw that the railroad would have to pass through that area to provide water for the steam locomotives. When crippled railroad tycoon Morton (Gabriele Ferzetti) learns of this, he sends his hired gun Frank (Henry Fonda) to intimidate McBain to move off the land, but Frank instead kills McBain and his three children, planting evidence to frame the bandit Cheyenne (Jason Robards). It appears the land has no owner; however, a former prostitute (Claudia Cardinale) arrives from New Orleans, revealing she is Jill McBain, Brett's new wife and the owner of the land.
Set in December, 1941, American expatriate Rick Blaine is the proprietor of an upscale nightclub and gambling den in Casablanca. "Rick's Café Américain" attracts a varied clientele: Vichy French, Italian, and German officials; refugees desperate to reach the still neutral United States; and those who prey on them. Although Rick professes to be neutral in all matters, it is later revealed he ran guns to Ethiopia during its war with Italy and fought on the Loyalist side against the fascist Nationalists in the Spanish Civil War.
At night in Paris, Driss is driving Philippe's Maserati at high speed. They are chased through the streets by the police, and eventually cornered. Driss claims the quadriplegic Philippe must be urgently driven to the emergency room; Philippe pretends to have a seizure and the fooled police officers escort them to the hospital.
The commercial spacecraft Nostromo is on a return trip to Earth with a seven-member crew in stasis. Detecting a mysterious transmission, possibly a distress signal, from a nearby planetoid, the ship's computer, MOTHER, awakens the crew. Following standard company policy for such situations, the Nostromo lands on the planetoid and Captain Dallas, Executive Officer Kane, and Navigator Lambert head out to investigate. They discover the signal is coming from a derelict alien spacecraft. Inside, they find the remains of a large alien creature whose ribcage appears to have exploded from the inside.
The unnamed narrator (Edward Norton) is a traveling automobile company employee who suffers from insomnia. One night he visits a support group for testicular cancer victims, where they assume that he too is a victim, and he spontaneously weeps into the nurturing arms of another man, finding a "freedom" that euphorically relieves his insomnia. He becomes addicted to participating in support groups of various kinds, always allowing the groups to assume that he suffers what they do. However, he begins to notice another impostor, Marla Singer (Helena Bonham Carter), whose presence disturbs his bliss, so he negotiates with her to avoid their attending the same groups.
In the Second Age of Middle Earth, the Dark Lord Sauron forges the One Ring in Mount Doom to conquer all. An alliance of men and elves battle Sauron’s forces in Mordor, where Isildur kills Sauron by chopping off the hand wearing the One Ring. Sauron's spirit survives within the ring and corrupts Isildur so that he keeps it instead of destroying it. This decision leads to Isildur's being killed by Orcs, and the ring is lost in the river Anduin for 2500 years. It comes into the possession of Sméagol who is consumed by its power and becomes Gollum. After 500 years the ring abandons him, to be discovered by a Hobbit named Bilbo Baggins.
In 1963 Oregon, Randle Patrick "Mac" McMurphy (Jack Nicholson), a recidivist anti-authoritarian criminal serving a short sentence on a prison farm for the statutory rape of a 15-year-old girl, is transferred to a mental institution for evaluation. Although he does not show any overt signs of mental illness, he hopes to avoid hard labor and serve the rest of his sentence in a more relaxed hospital environment.
Frodo Baggins and Samwise Gamgee continue their journey to Mordor to destroy the One Ring by throwing it into Mount Doom. They are attacked in the night by Gollum, former owner of the Ring, but they capture him. Sympathising with Gollum for their shared burden, Frodo asks Gollum to lead them safely to Mordor, despite Sam’s objections. Meanwhile, Aragorn, Legolas, and Gimli pursue the Uruk-hai who kidnapped their friends Merry and Pippin. The Uruk-hai are slaughtered by the Rohirrim army of Rohan, but the two Hobbits escape into Fangorn Forest where they meet the Ent Treebeard. Aragorn’s group later meet the Rohirrim who have been banished by their king Théoden, who is manipulated by Saruman’s servant Grima Wormtongue. Tracking the Hobbits in Fangorn, Aragorn’s group encounter a resurrected Gandalf who perished in Moria, but was revived to help save Middle Earth.
Crop blight has made growing food on Earth nearly impossible, threatening the existence of humanity. Joe Cooper, a widowed former NASA pilot, runs a farm with his father-in-law Donald, son Tom, and daughter Murphy. Murphy believes her bedroom is haunted by a poltergeist. When the "ghost" creates a pattern of dust on the floor, Cooper realizes an unknown intelligence is using gravity to communicate, and interprets the pattern as geographic coordinates, which Cooper and Murphy follow to a secret NASA installation.