In 2028, Earth is suffering from a global energy crisis. The space agencies of the world prepare to test the Shepard particle accelerator aboard the orbiting Cloverfield Station, which would provide Earth with infinite energy, while conspiracy theorists fear it will create the "Cloverfield Paradox", opening portals to parallel universes allowing their horrors to threaten Earth. Among the crew is Ava Hamilton (Gugu Mbatha-Raw), a British engineer who frets about leaving her husband Michael (Roger Davies) potentially for years, as their relationship struggles since the loss of their children to a house fire. The crew is rounded out by American commander Kiel (David Oyelowo), German physicist Ernst Schmidt (Daniel Brühl), Brazilian medical doctor Monk Acosta (John Ortiz), Irish engineer Mundy (Chris O'Dowd), Russian engineer Volkov (Aksel Hennie), and Chinese engineer Tam (Zhang Ziyi).Volkov blames Schmidt of deliberately trying to make the particle accelerator fail as back on Earth Russians are dying due to the energy crisis and Germany is preparing for an invasion of Russia.After about two years of unsuccessful attempts to activate Shepard, the crew achieves a seemingly stable beam, but it overloads and creates a power surge on the station. After restoring basic power, they find Earth has vanished from view, and the gyroscope that aids in the station's navigation is missing. As the crew works on repairs, strange events begin to occur, including the discovery (and subsequent rescue) of an unfamiliar woman called Mina Jensen (Elizabeth Debicki) fused with wires inside a wall. Volkov's eyeballs begin moving of their own accord; he begins conversing with his own reflection in a mirror and is compelled to craft a gun using an on-board 3D printer. He uses the gun to threaten the crew, but as he does so he convulses and dies, and the station's worm colony bursts out of him. Jensen wakes up and tells Hamilton not to trust Schmidt, who turns out to be a spy sent by the German government to keep Shepard shut down.Mundy's arm gets pulled into a solid wall and is severed clean off, without bleeding or pain. They find the arm roaming of its own volition. When they recognize it is trying to write something, it instructs them to "cut Volkov open". Once they do, they find the missing gyroscope. They finally locate Earth and begin restoring their communications, but transmissions state the station was destroyed and fell to Earth two days prior.Meanwhile back on "Earth" a monster has started unleashing chaos.The crew determine the particle beam overload has activated the Cloverfield Paradox, and in doing so, moving the station to a parallel universe in which Jensen had replaced Tam as the station's engineer, Schmidt was a spy, the countries are at war as the Cloverfield station was a failure and was destroyed trying to discover a limitless energy source, and Hamilton (though still working on the mission) remained on Earth, where her children were still alive. Believing the Paradox can be reversed, and they can return to their own universe if they reactivate the Shepard, the crew sets out to make repairs. Tam is trapped in a chamber that floods with water and explodes into space, killing her (after she had figured out that the Shepard needed to be ventilated in order to be fired again). This leaves the crew no choice but to use Jensen as the engineer for Shepard.Meanwhile, Hamilton decides to return to parallel Earth with Jensen in order to prevent the fire that killed her children (as in the current Universe, they are still alive, as per what Jensen tells her (as she and Jensen are deep friends in the current Universe)). As they prepare, Mundy is killed in an explosion caused by a strange magnetic field, destabilizing the bottom part of the Cloverfield station and threatening to tear the whole station apart. Kiel sacrifices himself to save the station, leaving Hamilton in charge.On Earth, Michael has woken up to discover a wave of destruction ravaging the planet, witnessing the silhouette of a giant monster in the distance. On his way to offer assistance at the local hospital, he stops to help a young girl named Molly at a dockyard. After learning the hospital was destroyed, he takes her to the underground shelter of a friend and tends to her wounds.With Shepard ready to activate again, Hamilton prepares to leave with Jensen, but Jensen suddenly knocks her out & puts her into a pod already programmed to return to Earth. Jensen kills Monk with Volkov's gun, wounds Schmidt, and insists the station must stay in her universe to keep Shepard there. Regaining consciousness, Hamilton decides to stay on station (to stop Jensen) & uses the gun to shoot out a window, ejecting Jensen into space. Hamilton decides to return to their universe with Schmidt and makes a recording for her alternate universe self, giving her the plans for Shepard and stressing the importance of her family. Hamilton and Schmidt reverse the universe shift and use Tam's modifications to finally make Shepard work. After reporting in, the two eject themselves in an evacuation capsule towards Earth.Michael learns from mission control of the station's reappearance and his wife's return to Earth, but he lambastes them for not warning her not to return to Earth in light of the ongoing situation. As the capsule re-enters the Earth's atmosphere, a giant monster bursts through the clouds.