Everyone dies except for Schmidt (Daniel Bruhl) and Hamilton (Gugu Mbatha-Raw). They take a pod from the space station back down to Earth, unaware that it is being attacked by monsters like the ones from the original "Cloverfield."
The Cloverfield space station is orbiting Earth in hopes of using a reactor to provide free energy to solve Earth's current energy crisis. A conspiracy theorist, Mark Stambler (Donal Logue), warns that the reactor could cause a dimensional rift, unleashing chaos into our reality.
After the crew of the station test the reactor, they see that Earth is missing. Strange things start happening after that: Mundy (Chris O'Dowd) loses his arm, which is found later writhing around on the floor. Volkov (Aksel Hennie) goes insane before vomiting worms and the station's navigation system is found in his stomach. A woman, Jensen (Elizabeth Debicki), is found inside the ship's electrical wires and she seems to know Hamilton, even telling her that Hamilton's children, who died in a fire, are still alive.
The crew realize that they are in another reality and that if they re-fire the reactor, it could send them home. Jensen, however, wants to use the reactor to save her reality from the war being fought on Earth over energy and kills a few crew members to steal it. Hamilton fights Jensen and leaves her to get sucked out of a broken airlock.
Hamilton and Schmidt, the only survivors, transmit plans for the reactor to the Earth in Jensen's reality. They re-fire the reactor, bringing them back to their reality and take a pod home, but as the pod lands, the original Cloverfield monster rises from the clouds and roars.