Gabriel Yulaw, once an agent of the MultiVerse Authority (MVA) which polices interdimensional travel, seeks to hunt down 124 variants of himself across parallel universes. By killing his other selves and absorbing their life energies, Yulaw believes that he will become a super-powered, godlike being called "The One". After killing Lawless, a convict and the 123rd variant in the Anubis Universe, Yulaw is captured by MVA agents Roedecker and Funsch and taken back to the MVA headquarters in the Alpha Universe. He is sentenced to life in the Hades Universe's Stygian penal colony, but Yulaw manages to escape with the help of an accomplice and teleports to the Charis Universe. The last known variant, Gabe Law, is a deputy sheriff working of the Los Angeles County Sheriff's Department within the Charis Universe. For two years, Gabe has been experiencing increases in strength, speed, and mental ability, but neither he nor his wife T.K. can understand why. While transporting a prisoner, Gabe "feels" Yulaw's presence in time to avoid being shot. Gabe sustains an injury after falling from a wall which Yulaw scales with ease. Roedecker and Funsch arrive in time to stop Yulaw from finishing him off. Although unfamiliar with interdimensional travel, Gabe realizes that Yulaw is identical to him in every way. Roedecker and Funsch track Yulaw to the hospital where Gabe is being examined. Yulaw deters them from shooting him because if he is killed, Gabe would then be left as the One. Dressed alike and identical to each other, Gabe and Yulaw's battle confuses the other police officers. Both Gabe and Yulaw manage to escape the hospital. The MVA agents deviate from their orders and split up. Roedecker pursues and fights Yulaw but is killed when the latter breaks his neck, disabling a bomb Roedecker intended to use to finish both of them off. Funsch catches up with Gabe and explains to him that there are multiple universes with wormholes briefly connecting them at uncontrollable times. Meanwhile, Yulaw sneaks into Gabe's residence where T.K., believing him to be Gabe, agrees to hide him from the police. She realizes that Yulaw is deceiving her but not in time to avoid being captured. Gabe arrives, only to watch helplessly as Yulaw kills T.K. Funsch finds a guilt-ridden Gabe and both team up to find Yulaw at the next wormhole. Gabe and Funsch arrive at an industrial plant, where they encounter and fight Yulaw. Funsch is easily defeated but Gabe and Yulaw are more evenly matched. Gabe manages to gain the upper hand but only seconds before the wormhole arrives. All three of them are sucked into it and collapse on the floor of the MVA headquarters. Yulaw is transported immediately to the Hades Universe after a failed attempt to switch places with Gabe. The MVA then prepares to send Gabe back to his own universe, where he will take the fall for Yulaw's crimes. Recalling an earlier conversation with Gabe, Funsch compassionately sends him to a different universe in which Gabe can have a normal life again from when he first met T.K. Now imprisoned in the Hades Universe, Yulaw declares that he will still become the One and then proceeds to battle several of the penal colony's inmates on top of a ziggurat.

An international consortium of scientists, operating as Project Inner Space in Tanganyika, Africa, is trying to tap into the Earth's geothermal energy by drilling a very deep hole down to the planet's core. The scientists are foiled by an extremely dense layer of material. To penetrate the barrier and reach the magma below, they intend to detonate an atomic device at the bottom of the hole. The leader of the project, Dr. Stephen Sorenson (Dana Andrews), who is secretly dying of cancer, believes that the atomic device will burn its way through the barrier, but the project's chief geologist, Dr. Ted Rampion (Kieron Moore), is convinced that the lower layers of the crust have been weakened by decades of underground nuclear tests, and that the detonation could produce a massive crack which would threaten the very existence of Earth. The atomic device is used and Rampion's fears prove justified, as the crust of the Earth develops an enormous crack that progresses rapidly along a fault line, causing earthquakes and tsunamis along its path. Rampion warns a committee of world leaders that the crack is capable of extending beyond the fault, and that if it were to encircle the Earth, causing the land masses to split, the oceans would be sucked in, generating steam at high enough of a pressure to rip the Earth apart. Sorenson meanwhile discovers that there was a huge reservoir of hydrogen underground, which turned the small conventional atomic explosion into a huge thermonuclear one that was millions of times more powerful. Another atomic device, lowered into the magma chamber of an island volcano in the path of the crack, is used in the hope of stopping the crack, but it only changes the crack's direction. Eventually, the crack approaches its starting point at the test site, and a huge chunk of the planet outlined by the crack is expected to be thrown out into space. Sorenson remains at the underground control center to record the event, despite pleas by his wife Maggie to evacuate with the rest of the project staff. She and Rampion barely escape the test site in time to observe the fiery birth of a second moon. Its release stops the crack, and the Earth survives.

In 2005, Alex lives in a village with his mother Klara and his cruel, unloving father Björn. Klara finally leaves the family, Alex's closest friend Anna moves to Stockholm, and Alex moves in with his uncle. Ten years later, Alex has become a famous musician in Stockholm. During Midsummer, the city is struck by multiple explosions, one of which kills his mother. Alex splits with his manager and goes back to his home village to buy the church piano that he and Anna used to play when they were younger. There, Alex again meets Anna, who has moved back to the village. When he learns that she has a husband, Kim, and daughter, Elin, he angrily departs. As attacks on Sweden worsen and the military is activated, people begin crashing their cars in the rain and Alex returns to help Anna and her family. After the Parliament is destroyed and communications networks become unavailable, Anna's mother, a government minister, manages to escape Stockholm and heads into the country, where she is rescued by the military. Meanwhile, Alex's father Björn, who works at a transformer station, kills a group of armed men who are attacking the electricity network. Helicopters and dead birds crash to the ground, apparently affected by contaminated rain, and civilians come to the station seeking safety in its bomb shelter. Among them are Anna and Alex, who is injured and unconscious. After Anna leaves in search of Elin, Alex comes to and tells his unapologetic father that Klara is dead. Anna returns with her daughter and tells Alex that her husband and many others were killed by helicopters. However, Kim is in fact alive. When helicopters approach the power station, the civilians head to the village church to meet the military, whom they have contacted by radio. The enemy attacks the military and kills Anna's mother, but Alex destroys an enemy helicopter by crashing a car into it and Björn takes down another helicopter by crashing his plane into it. He dies but saves Alex, Anna, and Elin. In the village church, which has been destroyed and is on fire, Alex tells Anna that Kim is still alive, then plays the piano until he loses his memory due to chemical weapons in the rain. Anna is taken away by Kim. News clips during the credits indicate that 800,000 Swedes have lost their memory, and images of Vladimir Putin suggest that Russia was behind the attacks.

James flees from a farmhouse and escapes into the woods. A screaming woman tries to follow, but is wounded by a gunshot. Lying on the ground, she is doused with gasoline and set on fire by Vincent and Simon. Deputy Sheriff Daniel Carter is on duty, sitting in his patrol car when he finds James crawling along the road and rushes him to the local hospital, which has been largely abandoned following a fire, where his estranged wife Allison Fraser works as a nurse. At the hospital are Dr. Richard Powell, nurse Beverly, intern Kim, pregnant patient Maggie, her grandfather Ben, and patient Cliff; with the staff at the hospital working as a skeleton crew. Daniel discovers an entranced Beverly murdering Cliff, her face flayed of skin. Beverly moves toward Daniel who shoots her dead. Daniel collapses due to a seizure and experiences a strange vision. State trooper Mitchell enters the hospital to collect James after discovering the bloody scene at the farmhouse. Daniel goes outside to call in Beverly's death from his patrol car but is tackled and stabbed by a robed cultist. He manages to return to the hospital as cultists surround the building. James, Daniel, and Mitchell find that Beverly's corpse has transformed into a tentacled creature. Vincent and Simon enter the lobby and hold the group at gunpoint, demanding to get to James. James takes Maggie hostage to protect himself and stabs Powell, who falls to the floor and dies. The Beverly-Creature appears and takes Mitchell, its tentacles penetrating his body. Vincent and Simon kill the Beverly-Creature and regroup with the others in the lobby, setting Mitchell's body on fire. Vincent and Simon accompany Daniel to retrieve a shotgun from a patrol car, while Allison ventures into the basement to collect medical supplies for delivering Maggie's baby. Powell, no longer dead, manages to capture Allison. Daniel and Vincent go to search for her and find photographs and files indicating Powell was the cult's leader. Powell phones Daniel from the in-house morgue, taunting him and mentioning the vision Daniel experienced while unconscious. Kim and Ben stay with Maggie while Daniel, Vincent, and Simon interrogate James. James explains that Powell has the power to transform people. The three men force James to come with them downstairs. Allison regains consciousness on an operating table where Powell explains he has found a way to defy death after the loss of his daughter Sarah. Having flayed off his face, Powell shows Allison that something now grows inside her belly. Daniel, Vincent, Simon, and James find a hidden area in the basement and end up surrounded by deformed corpses brought back to life. One of the creatures kills James as the other three men are separated. As Maggie enters labor, Kim hesitates to perform a C-section. As Ben pleads with Kim, Maggie stands and slits his throat, revealing she is carrying Dr. Powell's child. Kim hides as cultists enter the building and Maggie leaves to join Powell. Daniel finds Allison in the operating room pregnant. He sees a tentacled creature extending from her body. Powell's voice speaks to Daniel, who attacks his wife's mutated remains with an axe. Daniel is transported to a morgue room with a glowing triangle on the wall. Powell's voice tells Daniel that he found the ability to conquer life and death through a rite that enabled him to contact entities older than time itself. Powell promises that Daniel can have his child back if he is willing to die first. Maggie appears and stabs Daniel who is injured but alive. Powell appears skinless and partly mutated in front of the triangle as Maggie kneels before him. Powell recites an incantation before the triangle as a now frightened Maggie's torso explodes, giving birth to the Sarah-Creature. Vincent and Simon arrive and battle it. The Sarah-Creature overcomes Vincent, but he covers it in isopropyl alcohol, allowing Simon to set them both on fire with a flare. Powell tells Daniel he can be with Allison if he stops resisting and "let go". Daniel refuses and tackles him, leading both men to tumble into the void. Meanwhile, the Sarah-Creature pursues Simon, who escapes and is teleported back to the hospital to reunite safely with Kim. Daniel and Allison are shown holding hands in another world beneath a black pyramid while Powell's fate is left unknown.

In the year 2130, 547 days into its voyage, the spacecraft USS Palomino has nearly completed its mission exploring deep space. The crew consists of Captain Dan Holland, First Officer Lieutenant Charlie Pizer, journalist Harry Booth, ESP -sensitive scientist Dr. Kate McCrae, the expedition's civilian leader Dr. Alex Durant and the diminutive robot V.I.N.CENT. ("Vital Information Necessary CENTralized"). As it is returning to Earth, the Palomino discovers a black hole with the long-lost and apparently abandoned USS Cygnus nearby, the same ship that McCrae's father was aboard when it vanished 20 years prior. The Palomino decides to investigate and finds that there is a mysterious null gravity field surrounding the Cygnus that allows it to defy the massive gravitational pull of the black hole. The Palomino briefly strays outside the field and is damaged by the intense gravity, forcing it to emergency dock with the Cygnus, which no longer appears abandoned. The cautious Palomino crew soon encounter Dr. Hans Reinhardt (one of Earth's most brilliant scientists, according to Durant). Reinhardt explains he has been alone on the Cygnus since it encountered a meteor field and was disabled. He ordered the human crew to return to Earth without him, but McCrae's father chose to remain aboard and has since died. To replace the crew, Reinhardt built faceless, black-robed drones, sentry robots and his sinister bodyguard robot, Maximilian. Reinhardt says he intends to fly the Cygnus through the black hole because 20 years of study has shown that it is possible. Only an enamoured Durant believes him and asks if he can accompany Reinhardt. However, the rest of the Palomino crew start to become suspicious of Reinhardt. Booth sees a drone limping, while Holland witnesses an android funeral and discovers personal items in the Cygnus crew quarters. V.I.N.CENT. meets a battered earlier model of his type named BO.B. ("BiO-sanitation Battalion"). BO.B explains the drones are actually what is left of the human crew, who mutinied when Reinhardt refused to return to Earth after the Cygnus was damaged. McCrae's father was killed leading the mutiny, and the crew was lobotomized and "reprogrammed" to serve Reinhardt. V.I.N.CENT. uses telepathy to tell McCrae. After she informs Durant what really happened, he removes a drone's faceplate, revealing the zombie-like face of a crew member. Durant tries to flee with McCrae, but is killed by Maximilian. Reinhardt orders his robots to lobotomize McCrae, but just as the process begins, she is rescued by Holland, V.I.N.CENT. and BO.B. Harry Booth tries to escape alone in the Palomino, but is shot down and fatally crashes into the Cygnus. A subsequent meteor storm and the explosion of the ship's overstressed main power plant cause the anti-gravity generator to fail. Without its null-gravity bubble, the Cygnus quickly starts to break apart under the black hole's huge gravitational forces. Reinhardt and the Palomino survivors separately plan their escape in the probe ship used to study the black hole. Reinhardt orders Maximilian to prepare the ship for launch, but then a large viewscreen falls on Reinhardt, pinning him to the deck. His cries for help are not acknowledged by the lobotimized crew nor Maximilian, who enters the elevator as his master calls for him and pursues the Palomino crew as they attempt to escape. The crew nears the probe ship before being confronted again by Maximilian. He fatally damages BO.B. before battling with V.I.N.CENT. as McCrae, Holland and Pizer continue to the probe. V.I.N.CENT. defeats his opponent by drilling into Maximilian's armor, disabling his system and sending him hurtling into the black hole. Holland, Pizer, McCrae and V.I.N.CENT. launch the probe, which they soon realize has a pre-programmed flight path, taking them directly into the black hole. Within the black hole, the Cygnus completely breaks apart. The drifting Reinhardt and Maximilian merge above a burning, hellish landscape populated by dark-robed specters resembling Cygnus drones. Meanwhile, the probe ship is led through a cathedral-like arched crystal tunnel by a floating, angelic figure. After the ship emerges from a white hole, Holland, Pizer, McCrae and V.I.N.CENT. fly towards a planet near a bright star.

In 2009, American geologist Adrian Helmsley visits astrophysicist Satnam Tsurutani in Jharkhand, India, and learns that a previously undiscovered type of neutrino from a solar flare is heating the Earth's core. Returning to Washington, D.C., Adrian alerts White House Chief of Staff Carl Anheuser and President Thomas Wilson. A year later, over forty-six nations led by the G8 and China begin building nine arks in Tibet, while storing artifacts aboard them. Nima, a Buddhist monk, is evacuated with his grandparents, while his brother Tenzin joins the ark project. Additional funding is secretly raised by selling tickets to the rich for €1 billion per person. In 2012, struggling science-fiction writer Jackson Curtis is a chauffeur in Los Angeles for Russian billionaire Yuri Karpov. Jackson's former wife, Kate and their children, Noah and Lilly, live with Kate's boyfriend, plastic surgeon and amateur pilot Gordon Silberman. Jackson takes Noah and Lilly camping at Yellowstone National Park. When they find Yellowstone Lake dried up and fenced off by the United States Army, they are caught and brought to Adrian. They later meet conspiracy theorist and radio personality Charlie Frost, who tells Jackson of Charles Hapgood 's earth crust displacement theory and how the Mesoamerican Long Count calendar predicts the end of the world in 2012, and that the world's governments silence anyone attempting to warn the public. Despite his initial skepticism, Jackson begins to take Charlie's warning seriously after witnessing several signs that seem to confirm it. These include a conversation with Yuri's sons, Alec and Oleg, who warn of impending disaster after Jackson drops them off at Santa Monica Airport. He rents a Cessna 340A and sets out to rescue his family. As the Pacific Coast suffers a catastrophic 10.9-magnitude earthquake along the San Andreas Fault, Jackson and his family reach the airport and escape aboard the Cessna before the coast sinks into the Pacific Ocean. The group flies to Yellowstone, and Jackson retrieves Charlie's map of the Arks' location, just as the Yellowstone Caldera begins to erupt. Charlie stays behind to finish his broadcast and is killed by debris. Realizing they need a larger plane to fly to the Himalayas, the group lands at McCarran International Airport in Las Vegas to locate one. Adrian, Carl, and First Daughter Laura fly to the arks while President Wilson remains in the White House to address the nation. Jackson finds the Karpovs, Yuri's girlfriend Tamara, and their pilot, Sasha. Sasha and Gordon fly the families out in Yuri's Antonov An-500, as the volcanic ash from Yellowstone envelops Las Vegas. The planet's crust shifts, resulting in billions of deaths in disasters worldwide, including President Wilson. With the presidential line of succession broken, Carl appoints himself acting commander-in-chief. Upon reaching the Himalayas, the Antonov's engines malfunction. As the plane touches down on a glacier, the party uses a Bentley Flying Spur stored in the hold to escape, while Sasha stays in the cockpit and is killed when the jet goes over a cliff. The survivors are spotted by Chinese Armed Police helicopters which take only the three ticket-bearing Karpovs, and Yuri reveals his knowledge of Tamara and Sasha's affair, leaving Jackson's family and her behind. The group encounters Nima, who, with his own family, takes them to the arks, where they stow away on Ark 4 with Tenzin's help. With a megatsunami approaching, Carl orders the loading gates closed, though many people have not yet boarded. Adrian persuades the captain and the other surviving world leaders to allow more passengers aboard the arks, while Yuri falls to his death as he pushes his sons onto Ark 4. As the gate closes, Tenzin is injured and Gordon is fatally crushed. Tenzin's impact driver lodges in the gate mechanism, preventing it from closing completely and disabling the ship's engines. As the tsunami strikes, the ark starts flooding as it is set adrift, heading for Mount Everest. Adrian rushes to clear the gears, but watertight doors close, trapping the stowaways and drowning Tamara. Noah and Jackson dislodge the tool, and the crew regains control of the ark. Twenty-seven days later, the waters start receding. The arks approach the Cape of Good Hope, where the Drakensberg Mountains are now the highest mountain range on Earth. Adrian and Laura begin a relationship, while Jackson and Kate reconcile.

In the year 2058, an anomalously expanding red giant Sun threatens to engulf the Earth within 100 years. Under a world government, humanity has constructed 10,000 enormous fusion-powered "Earth Engines" to thrust Earth out of the Solar System and move it into a new orbit around Alpha Centauri. Before his mission aboard the Navigation Platform International Space Station, Chinese astronaut Liu Peiqiang leaves his son Qi in the care of his father-in-law Han Zi'ang. Half of humanity, mostly chosen by lottery, moves underground; the others die from the cold and cataclysms resulting from the halt of the Earth's rotation as the planet is thrust out of its orbit around the Sun. Seventeen years later, Peiqiang is about to return to Earth after the Chinese New Year. Qi, now an adult, obtains fake IDs and stolen thermal suits from criminal gangs and uses his grandfather's clearance pass to bring his foster sister, Han Duoduo, to tour the surface. Both are arrested at a checkpoint and meet another prisoner, Tim. Zi'ang is also arrested as he attempts to bribe for his grandchildren's release. As Earth approaches its gravity assist around Jupiter, a gravitation spike from Jupiter causes devastating earthquakes that disable many Earth Engines and sets the planet on a collision course with Jupiter. The four escape in the collapse and attempt to make their way to another underground city, but their truck is requisitioned for an emergency mission led by Captain Wang Lei to transport a Lighter Core to restart an Earth Engine in Hangzhou. In the frozen ruins of Shanghai, they lose their vehicle while transporting the component up the ruins of the Shanghai Tower, where Han Zi'ang freezes to death. After confronting the other rescue team members, Qi, Tim and Han Duoduo abandon the mission. The trio come upon a crashed cargo plane with an intact vehicle, where the surviving engineer aboard, Li Yiyi, eventually convinces them to transport another Lighter Core to repair the Earth Engine in Sulawesi, reconciling with the other members on the way. Aboard the space station, Peiqiang discovers that MOSS, the station's computer commander, has decided to abandon Earth and repurpose the station as an interstellar ark to seed a new planet with Earth's biosphere. Breaking out of forced hibernation, he is joined by fellow Russian cosmonaut Maxim Makarov, whom MOSS awakens to stop Liu. While spacewalking, Makarov is killed by the spacecraft's automated security measures. Liu enters the control room, but his attempts to override the evacuation procedures are revoked. Qi's group arrives at the Sulawesi Supply Depot to find that, while most engines around the planet have been restored, the combined thrust is insufficient to divert Earth's trajectory as it approaches Jupiter's Roche limit. MOSS broadcasts a final message to the world, but Peiqiang refuses to follow the computer's instructions. As Jupiter begins to siphon Earth's atmosphere, Qi proposes to ignite the oxygenated mixture of the two planets’ gases, which will cause a shockwave to knock Earth back into its regular path away from Jupiter. Yiyi configures the Sulawesi engine to fire a plasma beam tall enough to ignite Jupiter, but the group is unable to push the firing pin and ignite the engine. Contacted by Duoduo, Peiqiang is able to persuade the UEG to use its communication channels to call assistance for the party at Sulawesi despite MOSS' doubts. While other rescue parties manage to ignite multiple engines, they are unable to ignite the hydrogen. After starting a fire to disable MOSS, Peiqiang pilots the space station into the plasma jet, tearfully apologizing to his son for breaking his promise to return before sacrificing himself to ignite the mix of atmospheres. The subsequent explosion narrowly saves Earth from destruction. Three years later, Qi, Duoduo, and Yiyi work as truck operators, as Earth continues towards the Alpha Centauri star system.

In New York City, during the late 21st century, genetically altered humans live side by side with aliens and other beings, with the former lording over the latter and treating them as second class citizens. These beings have come to Earth as refugees via the "inclusion zone", a mysterious vortex which appeared one day, encompassing Central Park and sealing it off. The forcefield allows the refugees to exit, but anyone who tries to enter is instantly killed. A strange pyramid appears hovering over the city. Within, the gods of ancient Egypt discuss their fellow god Horus and conclude that his rebellious antics are unacceptable and must be punished, sentencing him to lose his immortality and summarily be executed. They grant Horus seven days to "look upon his creation", and inform him that the only way to save himself is to reincarnate in a new body. However, the only way to do this is to find and mate with a compatible woman capable of carrying a god's child, a trait which is extremely rare. In the city below, Jill, a young woman with blue hair and a fey countenance, is captured by agents of the all-powerful corrupt eugenics company that controls much of the government and private sector, who kidnap the alien refugees to experiment on them. She is humanoid in appearance, but not quite human; her tears are blue and stain her pure white skin, and upon being examined by the company's scientists, it is discovered that her body's cells are no more than three months old despite looking and acting like a fully grown adult. Unbeknownst to the scientists, Jill is a bioengineered being, explaining her human-like appearance and unusual paranormal abilities. One of these abilities is the aforementioned capacity to procreate with gods, but she is unaware of this, nor is she aware that she was created explicitly for this purpose. Her genome is rapidly adapting and changing into that of a regular human, with the tradeoff being that she will lose all memories of her former self once the transformation is complete. One of the scientists, Dr. Elma Turner, is fascinated by Jill's unique physiology and becomes enamored with her, subsequently helping facilitate her escape. Elsewhere, Horus begins his search for a mate, but time is short as not only is his execution looming, but Jill herself will lose her unique ability to bear his child once she becomes fully human. He must inhabit a mortal body to perform this task, but quickly finds that anyone he tries to possess self destructs in a gruesome manner. He deduces that humankind has become incompatible due to their genetic modification, and are thus incapable of handling his godly presence within them. Desperate to find a suitable host body, Horus eventually encounters Nikopol, a political rebel condemned to thirty years of hibernation who, due to a mechanical accident, escapes his imprisonment one year early when the wall of the cryo-prison crumbles. Nikopol, having been in cryostasis for several decades, has remained unmodified, and thus is able to be a host body for Horus to inhabit, much to Nikopol's chagrin. Horus possesses Nikopol's body but fails to take full control of him, causing the two to frequently clash with one another. Nikopol, having lost his leg as a result of the prison toppling, is given a replacement by Horus which he fashioned out of some steel railway track, with the comical side effect that it is too heavy for Nikopol to move on his own when he is in control of his body. Together, the two set out to fulfill Horus's quest. Nikopol and Horus eventually find Jill, and Horus begins to put his plan in motion by seducing her as Nikopol. Nikopol takes umbrage with this, decrying Horus's actions as sexual assault, which Horus thinks is merely a necessity and not wrong, as he is a god and therefore anything he does is, by definition, morally just. Nikopol begins to fall in love with Jill, further complicating matters. Meanwhile, a police inspector is investigating a series of serial killings in which the bodies of seemingly random individuals appear to have been torn apart from the inside out. The victims are the remains of the previous hosts Horus tried to inhabit, and Nikopol as well as Jill become suspects. Nikopol/Horus must woo Jill while simultaneously trying to keep her safe from the eugenics corporation, as well as staying one step ahead of the police. Eventually, Horus is successful and impregnates her in the nick of time, giving Nikopol's body back and leaving a parting gift by granting him the ability to move his heavy metal leg on his own. A year later, Nikopol bumps into a now fully human Jill in Paris with her new baby, a blue falcon who Jill describes as "cheeky". She does not remember him, but the two strike up a conversation, hinting that they may one day rekindle their romance. As the film ends, the camera pans up to the pyramid ship where Horus is entombed in a sarcophagus, a glimmer of light flashing in his eyes.

The four mathematicians are gathered and meet with a top official of the United States Department of Defense. After some discussion, the group agrees that they must be wary with whom to trust and control their solution. The official offers them a reward of $10 million in exchange for their portion of the algorithm, swaying them by attempting to address their concerns. Only one of the four speaks out against the sale, and in doing so is forced to reveal a dark truth about his portion of the solution. Before they sign a license to the government, however, they wrestle with the ethical consequences of their discovery.

The film opens with a montage of pollution, which, as implied by the narrator, is the cause of a virulent new disease arising in Asia, a virus that strikes all members of the grass family, including wheat, rice, and maize. It spreads to Africa, Europe and South America, bringing starvation, anarchy and cannibalism in its wake. Hundreds of millions die. The Chinese use nerve gas on their own population, killing 300 million, in their desperate attempts to survive. A year after the start of the disaster, John Custance, his family and his daughter Mary's boyfriend, scientist Roger Burnham, leave London during rioting just before roadblocks are set up. They head for his brother David's farm in the north. They stop at Mr. Sturdevant's shop to obtain firearms. When Sturdevant refuses to sell them any without the proper permits, John and Roger overpower him, but are held at gunpoint by his assistant, Andrew Pirrie. However, when John explains the situation to Pirrie, he shoots his employer, and he and his wife Clara join them. To get past an Army roadblock, they are forced to shoot three soldiers. Later, the party become separated when Roger and Pirrie race each other in their cars. John's car is stopped by a gate at a train crossing. He is knocked out, and his wife and 16-year-old daughter are taken away and raped by three men. John and the others find them and shoot two of the men, but one gets away. Later, they are stopped by vigilantes guarding their settlement and robbed of everything useful, including their vehicles and guns. Fortunately, they are only 50 miles (80 km) away from their goal. Now on foot, they come upon an isolated farmhouse. They kill the farmer and his wife and take their guns. While staying in an abandoned factory Pirrie's wife Clara attempts to seduce John and is shot by her husband. Mary and Pirrie become close, as Mary believes Pirrie can protect her. Next, they encounter a larger group trudging the other way. John offers to take them along to his brother's easily protected valley. Their leader objects and goes for his gun, so Pirrie shoots him. The others decide to join John's party. As they walk beside a road, a motorcycle gang rides by. John's wife Ann recognizes one of them as the escaped rapist. The armed gang mount a series of mounted attacks, but are killed in the ensuing gun battle, as are some of John's people. When they finally reach David's place, they see that it is well protected by a stone wall and a machine gun. David tells John privately that he cannot let such a large number of people in – the valley cannot feed so many – and suggests John sneak away from his group in the night with his family and Roger. Instead, John mounts a night attack. Pirrie shoots David, who is manning the machine gun, but is himself also killed. The attack is successful, and John takes charge of the valley.

Four teenagers – Kevin, Kathryn, Rudy, and Tish – and 12-year-old Max go to Space Camp, for three weeks during the summer to learn about the NASA space program and mimic astronaut training. They meet their instructor, Andie Bergstrom, a NASA-trained astronaut who is frustrated that she has not been assigned to a Space Shuttle mission. Her bitterness is compounded by the fact that her husband, camp director Zach Bergstrom, is an astronaut who has walked on the Moon. Max befriends a robot named Jinx, which was deemed unsuitable for space work because it overheated and was overly literal. Kathryn declares her dream to become the first female Shuttle commander and is frustrated when Andie assigns that role to Kevin instead to teach him responsibility. Kevin pursues Kathryn romantically, Rudy shares his wish to open the first fast food franchise on the Moon, and Tish reveals that despite appearing to be a valley girl, she is a genius with a photographic memory. Kathryn and Kevin sneak away for romance near the launch pad, but Jinx unintentionally gives them away. Andie explains that she believes Kathryn has what it takes to accomplish her ambition and explains the necessity of the harsh treatment she is giving her. Kevin takes out his anger on Max. Upset, Max states, "...I wish I was in space." Jinx overhears and takes what Max said literally. The campers are allowed to sit in the Space Shuttle Atlantis during a routine engine test. Jinx secretly enters NASA's computer room and triggers a "thermal curtain failure," causing one of the boosters to ignite during the test. In order to avoid a crash, Launch Control ignites the second booster and launches the Shuttle. The Shuttle is not flight ready, has no long-range radio, and has insufficient on-board oxygen to last to the re-entry window at Edwards Air Force Base. Andie takes the Shuttle to the partially constructed Space Station Daedalus to retrieve oxygen stored there. Realizing that while they have no voice communications with NASA they do have telemetry, Tish uses a switch to send a morse code signal to NASA, but it is not noticed by ground control. Andie is too big to reach the oxygen cylinders, so Max suits up for an EVA. During a critical moment, he panics until Kevin, knowing that Max is a fan of Star Wars, begins calling him "Luke" and tells him to "use the Force ", which calms him enough to complete the mission. In the Shuttle, Rudy attempts to decipher the technical schematics to work out how to feed the oxygen into the Shuttle's tanks. His lack of confidence combined with the time pressure frustrates Kathryn, who gives Andie instructions that conflict with Rudy's. Andie follows Rudy's correct instructions. Kathryn's self-confidence is shaken as she realizes her interference nearly caused disaster. The second oxygen tank malfunctions, injuring Andie. Unaware of this, Ground Control begins the autopilot sequence to land the Shuttle – closing the bay doors and stranding Andie outside. She regains consciousness and urges them to leave her and take the re-entry window, as the Shuttle does not have enough oxygen to make the next window. Kathryn is unable to make a decision, but Kevin overrides the autopilot, enabling Max to rescue Andie. Having missed the Edwards re-entry window, the crew comes up with a plan to land at White Sands, New Mexico, after Rudy recalls the 1982 Space Shuttle mission that landed there. Tish uses Morse Code to signal NASA to let them land there. At Ground Control, Jinx brings the signal to Zach's attention, and they prepare for the White Sands landing. With Andie injured, Kathryn fulfils her role as Shuttle Pilot, but doubts her abilities until Kevin cajoles her into guiding Atlantis through re-entry and landing it at White Sands.

Searching for a way to address overpopulation and global warming, Norwegian scientist Dr. Jørgen Asbjørnsen develops "downsizing", an irreversible process that shrinks organic material. He becomes part of the first group of human test subjects and is encouraged that the process reduces people to a height of approximately 5 inches (13 cm), drastically decreasing their consumption and waste. When the findings are revealed at a conference five years later, there is a global sensation. Ten years later, Paul and Audrey Safranek, a financially struggling married couple in Omaha, see Dave and Carol Johnson, who have downsized, at Paul's high school reunion. Rather than the touted environmental benefits, Dave argues the real reason to downsize is that one's money goes much further when one is small. Paul and Audrey decide to undergo the procedure and move to Leisureland, New Mexico, one of the fancier communities for small individuals. In a Leisureland recovery room after the procedure, Paul receives a call from Audrey, who says she backed out at the last minute and, because they are now different sizes, is leaving him. Because of his reduced size Paul has no choice but to take up solitary occupancy of a sprawling and luxurious mansion, previously selected by the couple using their greatly enhanced capital. Leisureland is presented as an attractive but bland consumerist enclave for the newly rich and downsized, protected by high walls and a dome. A year later, Paul signs his divorce papers. Unable to afford the mansion Audrey chose, he relocates to an apartment and takes a job as a customer service representative at Lands' End. He had let his occupational therapy license lapse, not anticipating the need to work after being shrunk. He has started dating someone, but they break up, and Paul finds himself at a wild party thrown by his shady yet charming neighbor, Dusan. The next morning, Paul recognizes one of Dusan's house cleaners as Ngoc Lan Tran, a Vietnamese political activist who was jailed and downsized against her will, escaped in a television box, barely survived being shipped to the United States, and was brought to Leisureland a year ago to have her leg amputated. Wanting to assist Ngoc Lan with her prosthetic leg, Paul goes to her apartment in the slums just outside the walls of Leisureland where those who had no money when they downsized or downsized illegally who now work as the service workers of the community live. Paul had not thought about this part of the small economy, and is shocked by conditions in the slum. At her apartment, Ngoc Lan has Paul try to help her dying friend. When she finally lets him work on her prosthetic leg, he breaks it, so, until she can get a new one, he agrees to work for her cleaning service and also help her gather food from around the city to distribute throughout the slums. Dusan, upon learning what Paul is doing, attempts to release Paul from his obligation by taking him to deliver supplies to the original colony for small people, but Ngoc Lan unexpectedly decides to tag along, as she has a standing invitation to visit Dr. Asbjørnsen, who had heard about her ordeal. In a Norwegian fjord, Dr. Asbjørnsen and his wife board the boat piloted by Dusan's friend Joris Konrad. Dr. Asbjørnsen announces it has just been determined conclusively that, due to the positive feedback of Antarctic methane emissions, the human race will soon become extinct. Paul asks if downsizing can save humanity, but Dr. Asbjørnsen says the procedure came too late, as only three percent of the world has so far chosen to downsize. That night, Paul and Ngoc Lan have sex. At the colony, the travelers discover that, the next day, Dr. Asbjørnsen is enacting a contingency plan: he and the other colonists are going to enter a large underground vault, and their descendants will emerge when the surface environment stabilizes in about eight thousand years. Dusan and Joris are skeptical of the cult-like plan and say the extinction will not happen for hundreds of years, while Paul is excited to enter the vault and help with this effort to ensure the future of mankind. He asks Ngoc Lan to join him, but she refuses, saying the people in need of help will be those left above ground. As the door of the vault is closing, Paul changes his mind and steps outside. Back in Leisureland, Paul continues to work with Ngoc Lan to serve the people of the slums, deriving contentment from things like bringing dinner to an old man.