In the near future, an environmental cataclysm forces the human race to abandon Earth and venture beyond the Solar System in search of a new home. The exodus ends when humanity settles a new pristine world they call, Nova Prime.
One thousand years later, The Ranger Corps, a peacekeeping organization commanded by General Cypher Raige (Will Smith), comes into conflict with the S’krell, alien creatures that intended to conquer Nova Prime. Their secret weapon are the Ursas, large predatory creatures that hunt by ‘sensing’ fear. The Rangers struggle against the Ursas until Cypher learns how to completely suppress his fear, a technique called “ghosting”. After teaching this technique to the other Rangers, he leads the Ranger Corps to victory.
Meanwhile, Cypher’s son, Kitai Raige (Jaden Smith), blames himself for the death of his sister, Senshi (Zoë Kravitz), at the hands of an Ursa. Not wanting to fail his father again because of her death, Kitai trains hard to become a Ranger just like Cypher. His application for the Ranger Corps is rejected due to his recklessness, and Cypher views him as a disappointment. Kitai’s mother, Faia (Sophie Okonedo), convinces Cypher to take Kitai on his last voyage before retirement.
Forced together by the mission, father and son start to bond during the trip. However, their spaceship is caught by an asteroid shower forcing them to crash-land on Earth, now a Class-1 quarantined planet. Both of Cypher’s legs are broken, and the main emergency beacon has been damaged. Cypher instructs Kitai to locate the tail section of the ship which broke off during the plunge to the surface. Inside is the backup beacon which they can use to signal Nova Prime. Kitai is given Cypher’s Ranger weapon, a wrist communicator and six oxygen capsules so he can breathe, since human lungs can no longer tolerate Earth’s air. Cypher warns him to avoid the fauna and flora, which has mutated since humans left, and be careful with the planet’s thermal shifts. Kitai sets off to find the tail section, with Cypher guiding him through the communicator.
Kitai is soon attacked by giant baboons and ends up being bitten by a poisonous leech after going against Cypher’s orders in an attempt to escape. Although Kitai successfully administers an antidote, two of his oxygen capsules are damaged, and his nervous system shuts down for hours. When Kitai awakens, he narrowly escapes one of the planet’s thermal shifts, and upon discovery of his damaged capsules, lies to Cypher. That night, Kitai listens to Cypher tell him a story of when he was attacked by an Ursa, how he realized that fear is merely an illusion created by the mind’s thoughts of the future, and thus he first began to “ghost” himself from the Ursas, choosing to live rather than to let his enemy, both fear and the Ursas, decide his fate.
The following day, Kitai reaches a mountaintop, and Cypher learns about Kitai’s broken oxygen capsules. Concluding that Kitai won’t have enough oxygen, orders him to abort the mission. Believing his father still sees him as a disappointment, Kitai blames Senshi’s death on Cypher, who was away from Nova Prime the day they were attacked. Determined to prove his father wrong, Kitai skydives from the mountaintop, but is captured by a massive condor which damages his forewam/wrist communicator in the process.
The condor takes a liking to Kitai, who is forced to flee when the condor’s nest is attacked by tigers. Using a makeshift raft he continues his trek, during which Kitai has a dream about his sister. Senshi reassures him that Cypher’s bitterness is just his own anger for not saving her. When Kitai wakes, he is surprised by another thermal shift, loses Cypher’s weapon and nearly freezes to death. Fortunately, Kitai is rescued by the condor, that sacrifices itself for him.
Kitai reaches the tail section and retrieves the emergency beacon along with another communicator, weapon and more oxygen capsules. The communicator only allows Cypher to hear and see Kitai, but not for Kitai to hear him. Kitai is shocked to learn the ship was carrying an Ursa meant to teach the cadets how to “ghost” themselves. The creature has escaped in the crash and killed the remnants of the crew. When the emergency beacon does not activate, Cypher realizes that the atmosphere is blocking the signal, and that Kitai must get to higher ground. Kitai heads to a nearby volcano from which he can launch the beacon, where he is attacked by the Ursa and injured. However, remembering both Cypher’s instructions, focusing on the moment rather than the outcome, and the words of encouragement Senshi whispered in his dream, Kitai is able to control his fear and “ghost” himself from the Ursa enough to kill it with his weapon. Kitai then launches the beacon and a rescue mission soon arrives to return them to Nova Prime.
Cypher recovers from his injuries and salutes Kitai for his bravery.