Le Titan Thanos ayant réussi à s'approprier les six Pierres d'Infinité et à les réunir sur le Gantelet doré, a pu réaliser son objectif de pulvériser la moitié de la population de l'Univers d'un claquement de doigts. Les quelques Avengers et Gardiens de la Galaxie ayant survécu, Captain America, Thor, Natasha Romanoff, Bruce Banner, War Machine, Nébula et Rocket, espèrent réparer le méfait de Thanos. Ils le retrouvent mais il s'avère que ce dernier a détruit les pierres et Thor le décapite. Cinq ans plus tard, alors que chacun essaie de continuer sa vie et d'oublier les nombreuses pertes dramatiques, Scott Lang, alias Ant-Man, parvient à s'échapper de la dimension subatomique où il était coincé depuis la disparition du Docteur Hank Pym, de sa femme Janet Van Dyne et de sa fille Hope Van Dyne. Lang propose aux Avengers une solution pour faire revenir à la vie tous les êtres disparus, dont leurs alliés et coéquipiers : récupérer les Pierres d'Infinité dans le passé grâce à l'univers quantique.
By 2154, humans have depleted Earth's natural resources, leading to a severe energy crisis. The Resources Development Administration, RDA for short, mines for a valuable mineral – unobtanium – on Pandora, a densely forested habitable moon orbiting the gas giant Polyphemus in the Alpha Centauri star system. Pandora, whose atmosphere is poisonous to humans, is inhabited by the Na'vi, 10-foot tall (3.0 m), blue-skinned, sapient humanoids who live in harmony with nature and worship a mother goddess called Eywa.
The Asgardian Loki encounters the Other, the leader of an extraterrestrial race known as the Chitauri. In exchange for retrieving the Tesseract, a powerful energy source of unknown potential, the Other promises Loki an army with which he can subjugate Earth. Nick Fury, director of the espionage agency S.H.I.E.L.D., and his lieutenant Agent Maria Hill arrive at a remote research facility during an evacuation, where physicist Dr. Erik Selvig is leading a research team experimenting on the Tesseract. Agent Phil Coulson explains that the object has begun radiating an unusual form of energy. The Tesseract suddenly activates and opens a wormhole, allowing Loki to reach Earth. Loki takes the Tesseract and uses his scepter to enslave Selvig and a couple of agents, including Clint Barton, to aid him in his getaway.
Dévasté par la disparition d'Iron Man, son mentor, Peter Parker a pour projet de laisser son costume de super-héros derrière lui pendant quelques semaines afin de partir en vacances en Europe avec ses camarades lycéens, mais cette escapade est rapidement compromise quand il accepte à contrecœur d'aider Nick Fury à découvrir le mystère de plusieurs attaques de créatures, qui ravagent le continent.
In 1961, the Ark, a Cybertronian spacecraft carrying an invention capable of ending the war between the Autobots and Decepticons, lands on the far side of the Earth's Moon. The crash is detected on Earth by NASA, and President John F. Kennedy authorizes a mission to put a man on the Moon as a cover for investigating the craft. In 1969, the crew of Apollo 11 lands on the Moon to explore the craft.
Sixty-five million years ago, the alien race known as the "Creators" invade Earth, wiping out most of life on the planet including the dinosaurs with the "Seeds", and cyber-form thousands of planets, including Cybertron. In the present, Darcy Tirrel discovered frozen dinosaur corpses in the Arctic.
In 17,000 B.C., the Seven Primes traveled the galaxy to create Energon with star-absorbing machines called Sun Harvesters. The Primes followed a rule in which to never destroy planets with life, but one of them, later called The Fallen, deceives the others by building an army and sets up a Harvester on Earth. After defeating ancient humans, the Primes defeat and imprison the Fallen before he can harvest the Earth's sun with the Matrix of Leadership. The rest of the Primes sacrifice themselves to hide the Matrix.
On July 2, a 500 km wide alien mothership enters Earth's orbit and deploys several dozen saucer-shaped "destroyer" spacecraft, each 15 miles (24 km) wide. As they take position over some of Earth's major cities, David Levinson (Jeff Goldblum), an MIT graduate working for a cable company in New York City, discovers hidden transmissions in Earth's satellites which he realizes is a timer counting down to a coordinated attack by the aliens. With the support of his estranged wife Constance Spano (Margaret Colin), the White House Communications Director, he and his father Julius (Judd Hirsch) gain entrance into the Oval Office to notify President Thomas J. Whitmore (Bill Pullman) about the attack. Whitmore orders large-scale evacuations of the targeted cities, but the aliens attack with advanced directed-energy weapons before these can be carried out. Whitmore, portions of his staff, and the Levinsons narrowly escape aboard Air Force One as Washington, D.C. is destroyed.
In 2009, American geologist Adrian Helmsley visits astrophysicist Satnam Tsurutani in India and learns that neutrinos from a massive solar flare are causing the temperature of the Earth's core to rapidly increase. Arriving at a party in Washington, D.C, Helmsley presents his information to White House Chief of Staff Carl Anheuser, who takes him to meet the President.
The planet Krypton faces imminent destruction due to its unstable core; the result of depleting Krypton's natural resources. The ruling council is deposed by the planet's military commander, General Zod, and his followers during a coup d'état. Knowing that artificial population control and isolationism have ruined their civilization, scientist Jor-El and his wife Lara launch their newborn son, Kal-El, the first naturally born Kryptonian child in centuries, on a spacecraft to Earth after infusing his cells with a genetic codex of the entire Kryptonian race. After Zod kills Jor-El, he and his followers are captured and exiled to the Phantom Zone. However, they are indirectly freed after Krypton explodes, rendering the Kryptonian race extinct apart from Zod and his forces.
In the future, robots known as Sentinels are exterminating mutants and their human allies. A band of mutants, including Kitty Pryde, Colossus, Iceman, Bishop, Warpath, Blink and Sunspot, evade the Sentinels due to Pryde's ability to send a person's consciousness to the past. Pryde's group convenes with Logan, Storm, Professor Charles Xavier, and Erik Lehnsherr at a monastery in China. Pryde sends Logan's consciousness 50 years back in time to 1973 to prevent Mystique from assassinating Dr. Bolivar Trask, creator of the Sentinels. Following the assassination, Mystique was captured, and her DNA was used by Trask's company to improve the Sentinels, whose ability to adapt to any mutant power makes them almost invincible. Xavier and Lehnsherr advise Logan to find both of their younger selves for help.
Six months after the events of the first film, Neo and Trinity are now lovers. Morpheus receives a message from Captain Niobe of the Logos calling an emergency meeting of all of Zion's ships. Zion has confirmed the last transmission of the Osiris: an army of Sentinels is tunneling towards Zion and will reach it within 72 hours. Commander Lock orders all ships to return to Zion to prepare for the onslaught, but Morpheus asks one ship to remain in order to contact the Oracle. The Caduceus receives a message from the Oracle, and the Nebuchadnezzar ventures out so Neo can contact her. One of the Caduceus crew, Bane, encounters Agent Smith, who takes over Bane's avatar. Smith then uses this avatar to leave the Matrix, gaining control of Bane's real body.
Ten years after the worldwide pandemic of the deadly ALZ-113 virus (known as the Simian Flu), human civilization is completely destroyed following martial law, civil unrest and the economic collapse of every country in the world. Over 90% of the human population has died in the pandemic, while apes with genetically enhanced intelligence have started to build a civilization of their own.
Many years ago, the planet Cybertron was consumed by a civil war by the two Transformer factions, the Autobots led by Optimus Prime, and the Decepticons led by Megatron. Optimus jettisoned the AllSpark, a mystical artefact that brings life to the planet, into space, but Megatron pursued it. Megatron crashed in the Arctic Circle and froze, discovered in 1897 by explorer Archibald Witwicky. Witwicky activated Megatron’s navigational system, which scanned the AllSpark’s coordinates into his glasses. The glasses end up in the possession of his great-great-grandson Sam Witwicky. In the present day, Sam buys his first car, a rusting Chevrolet Camaro, but discovers it has a life of its own.
In District 12, Katniss Everdeen volunteers when her younger sister Primrose is initially chosen by lot. She and the male Tribute, Peeta Mellark, are escorted to the Capitol by chaperone Effie Trinket and their mentor Haymitch Abernathy, a past District 12 victor and alcoholic. Haymitch impresses on them the importance of gaining sponsors, as they can provide gifts of food and supplies during the Games. During part of a series of televised interviews, Peeta publicly expresses his love for Katniss, which she initially takes as an attempt to earn sponsor favor, but later learns his love is genuine. While training, Katniss observes the Career Tributes Marvel, Glimmer, Cato, and Clove, from Districts 1 and 2, who have been training for the Games since a young age.