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 a California forest, a group of alien botanists collect flora samples. When government agents appear on the scene, they flee in their spaceship, leaving one of their own behind in their haste. The scene shifts to a suburban home, where a 10-year-old boy named Elliott is trying to spend time with his 15-year-old brother, Michael, and his friends. As he returns from picking up a pizza, he discovers that something is hiding in their tool shed. The creature promptly flees upon being discovered. Despite his family's disbelief, he leaves Reese's Pieces candy to lure it to his bedroom. Before he goes to sleep, he realizes it is imitating his movements. He feigns illness the next morning to stay home from school and play with it. Later that day, Michael and their five-year-old sister, Gertie, meet it. They decide to keep it hidden from their mother, Mary. When they ask it about its origin, it levitates several balls to represent its solar system and then demonstrates its powers by reviving a dead chrysanthemum.
In 1957, Indiana Jones and his partner George "Mac" McHale are kidnapped in Nevada by Soviet agents under Colonel Dr. Irina Spalko. The Soviets infiltrate warehouse labeled "Warehouse 51" and force Jones to locate an alien corpse with a crystal skull, recovered ten years earlier. Upon its discovery, Mac reveals he is a double agent working for the Soviets. Jones escapes, unsuccessfully attempts to retrieve the skull, and in a fight with Spalko's sadistic henchman, Colonel Antonin Dovchenko, they both fall onto a rocket sled, which ignites and speeds them away. Jones staggers away and, still pursued, arrives in a model town at the Nevada Test Site, minutes before an atomic bomb test, and takes shelter in a lead-lined refrigerator. Jones is rescued, decontaminated, and arrested by FBI agents, who suspect him of working for the Soviets; and though freed on the recommendation of General Ross, who vouches for him, he is put on indefinite leave of absence from Marshall College.
The galaxy is in a civil war, and spies for the Rebel Alliance have stolen plans to the Galactic Empire's Death Star, a heavily armed and armored space station capable of destroying entire planets. Rebel leader Princess Leia is in possession of the plans, but her ship is captured by Imperial forces under the command of the evil Lord Darth Vader. Before she is captured Leia hides the plans in the memory of an astromech droid called R2-D2, along with a holographic recording. The droid, accompanied by fellow protocol droid C-3PO, escape from the captured ship to the desert planet Tatooine.
In 1988, following his mother's death, a young Peter Quill is abducted from Earth by the Ravagers, a group of space pirates led by Yondu Udonta. Twenty-six years later on the planet Morag, Quill steals an orb, after which Korath, a subordinate to the fanatical Kree, Ronan, intercepts him. Although Quill escapes with the orb, Yondu discovers his theft and issues a bounty for his capture, while Ronan sends the assassin Gamora after the orb.
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.
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.
Alimenté par sa foi restaurée en l’humanité et inspiré par le sacrifice de Superman, Batman constate l'arrivée d'éclaireurs extraterrestres — appelés "Paradémons" et attirés par la peur de leurs victimes — et comprend que l'attaque majeure prophétisée par Lex Luthor (dans le film Batman v Superman : L'Aube de la justice) est imminente, or Superman est mort et ne peut plus protéger l'humanité. Conscient de ses propres limites, il contacte Diana Prince/Wonder Woman et tente de former avec elle une ligue de super-héros. Il part retrouver Arthur Curry, dit Aquaman, qui habite à Atlantis, tandis que Diana va approcher Victor Stone, footballeur devenu à moitié machine après un accident et capable d'influer sur les technologies, mais les deux hommes refusent de les aider. Barry Allen, jeune homme doté de super-vitesse, accepte avec enthousiasme l'offre de Bruce Wayne.
Ten years after the Trade Federation's invasion of Naboo, the Galactic Republic is threatened by a Separatist movement organized by former Jedi Master Count Dooku. Senator Padmé Amidala comes to Coruscant to vote on a plan to create an army of the Republic to assist the Jedi against this threat. Narrowly avoiding an assassination attempt upon arrival, she is placed under the protection of Jedi Knight Obi-Wan Kenobi and his apprentice Anakin Skywalker. The two Jedi thwart another attempt on her life and subdue the assassin, Zam Wesell, a shape-shifter who is killed by her bounty hunter client with a toxic dart before she can reveal his identity. The Jedi Council assigns Obi-Wan to identify and capture the bounty hunter, while Anakin is assigned to escort Padmé back to Naboo, where the two fall in love.
In 2012, an alien criminal, Boris the Animal, a Boglodite, escapes from a maximum-security prison on the moon and arrives on Earth, bent on taking revenge on Agent K, who shot off his left arm and captured him in 1969. He confronts K, who is with his partner Agent J, telling him he is "already dead". J then discovers that K was responsible not only for capturing Boris, but for deploying the "ArcNet", a shield that prevented the Boglodites from conquering Earth and caused their extinction.
The narrator (Morgan Freeman) explains how humans were unaware that intelligent extraterrestrials were making plans to occupy Earth. Ray Ferrier (Tom Cruise) is a divorced crane operator longshoreman who works at a dock in Bayonne, NJ. Ray is estranged from his children. His former wife, Mary Ann (Miranda Otto), later drops off the children, 10-year-old daughter Rachel (Dakota Fanning) and teenage son Robbie (Justin Chatwin), at Ray's house in Bayonne on her way to visit her parents in Boston. Unexplained changes in the weather occur, emitting lightning that strikes multiple times in the middle of an intersection and disrupting all electrical technology in the area.
Agent K and his partner Agent D intercept a truck smuggling illegal immigrants into the United States. Inside they discover an alien disguised as a human. When he runs, they shoot him and use neuralyzers to wipe the memories of the border patrol witnesses. D decides to retire and asks K to wipe his memory too. In upstate New York, an alien crash-lands and kills an abusive farmer named Edgar to use his skin as a disguise.
Luke Skywalker initiates a plan to rescue Han Solo from the crime lord Jabba the Hutt with the help of Princess Leia, Lando Calrissian, Chewbacca, C-3PO, and R2-D2. Leia infiltrates Jabba's palace on Tatooine disguised as a bounty hunter with Chewbacca as her prisoner. Lando is already there disguised as a guard. Leia releases Han from his carbonite prison, but she is captured and enslaved. Luke arrives soon afterward but after a tense standoff, he is captured. After Luke survives his battle with Jabba's Rancor, Jabba sentences him and Han to death by feeding them to the Sarlacc. Luke frees himself and battles Jabba's guards. During the chaos, Boba Fett, who has remained at Jabba's palace since delivering Han, attempts to attack Luke, but Han inadvertently knocks him into the Sarlacc pit. Meanwhile, Leia strangles Jabba to death, and Luke destroys Jabba's sail barge as the group escapes. While the others rendezvous with the Rebel Alliance, Luke returns to Dagobah where he finds that Yoda is dying. Before he dies, Yoda confirms that Darth Vader, once known as Anakin Skywalker, is Luke's father, and there is "another Skywalker". The spirit of Obi-Wan Kenobi confirms that this other Skywalker is Luke's twin sister, Leia. Obi-Wan tells Luke that he must fight Vader again to defeat the Empire.
Three years after the destruction of the Death Star, the Rebel Alliance has been driven from their former base on Yavin IV by the Galactic Empire. Princess Leia leads a contingent including Han Solo and Luke Skywalker in a new base on the icy planet Hoth. The Imperial Fleet, led by Darth Vader, continues to hunt for Rebels’ new base by dispatching probe droids across the galaxy.
In 1954, a nuclear bomb is detonated at the moment a giant creature emerges from the ocean. In 1999, Project Monarch scientists Ishiro Serizawa and Vivienne Graham investigate a colossal skeleton unearthed in a collapsed mine in the Philippines. They find two spores; one dormant and one hatched that made a trail into the sea. In Japan, the Janjira Nuclear Power Plant experiences unusual seismic activity and Supervisor Joe Brody sends his wife Sandra and a team of technicians into the reactor. A tremor breaches the reactor, leaving Sandra and her team unable to escape while the plant collapses.