65 million years ago, on the exotic planet Somaris, pilot Mills (played by Adam Driver) persuades his wife Alya (portrayed by Nika King) to allow him to embark on a two-year space expedition. The mission promises to triple his salary, providing the funds necessary for the medical treatment of their sick daughter, Nevine (played by Chloe Coleman). However, tragedy strikes when a disaster occurs during the journey, and Mills’s ship, the Zoic, is struck by a barrage of asteroids, leading to a catastrophic crash landing on what he believes is an alien world—unbeknownst to him, it is actually Earth.
Upon awakening from cryogenic sleep, Mills finds himself alone, the only survivor of the ship's crew, as the other passengers lie lifeless around him. In a moment of despair, he considers ending his life but is soon met with unexpected hope when he discovers a young girl named Koa (played by Ariana Greenblatt), who has also survived. Mills sends out a distress signal and chooses to protect Koa, but this proves challenging as they struggle to communicate due to language barriers and a malfunctioning translator.
As they traverse the perilous new terrain, Mills explores the surrounding area and encounters remnants of ancient dinosaurs alongside steaming geysers. He learns of an escape shuttle from the Zoic that has landed atop a distant mountain, 15 kilometers away. To motivate Koa to join him, he fabricates a story about her family being safe up there, concealing the heartbreaking truth that they perished in the accident.
Their adventure quickly turns dangerous as they face aggressive alien creatures, which are actually dinosaurs. Mills bravely defends Koa as they begin to develop a close bond amidst this chaos. Armed with a device that indicates safe food options, Mills protects her from poisonous berries. The tension heightens when Koa watches a video message from Nevine, leading to an emotional awakening for Mills. The duo soon encounters a fierce creature, and during the chaos, an insect infiltrates Koa’s mouth, leading to a critical rescue by Mills.
As they navigate a dark cave, a T-Rex forces them deeper inside, prompting action from Mills as he shoots the beast to protect Koa. He gives her some bombs should they become separated, and when a rockfall traps him inside, Koa escapes into the lush jungle. There, she finds a large dinosaur tooth and cleverly fashions it into a weapon using a paste made from the poisonous berries.
Both face dire threats—Mills battles an Oviraptor, while Koa, employing her newfound intelligence and the bombs Mills gifted her, safely defeats a raptor-like creature. However, their ordeal escalates: Mills finds himself engulfed in quicksand, only to be saved by Koa as they make their way up the mountain. Unfortunately, Mills soon realizes that another asteroid is on a collision course with Earth, set to strike within 12 hours.
Upon reaching the escape shuttle, Koa is hurt to learn about Mills’s lies. In a moment of vulnerability, Mills reveals the devastating loss of Nevine, who succumbed to her illness while he was away. This newfound honesty strengthens their bond. As they prepare for rescue, disaster strikes again when debris from the asteroid impacts the shuttle, dislodging it from its launch position.
In a gripping fight for survival, Mills and Koa fend off two towering Tyrannosaurus Rexes. Mills bravely ventures outside for a weapon but faces setbacks with a faulty gun. Using a clever ruse involving a projection of Nevine, Koa distracts one of the predators, allowing Mills to take a shot at it. Just as they think they have escaped danger, the massive Theropod they wounded earlier returns, leading to a frantic escape sequence. As Mills expertly lures the creature toward a geyser, Koa uses her poison-coated tooth for a decisive strike.
With time running out from the impending asteroid collision, the pair manage to launch the escape pod just as chaos erupts around them. They witness the cataclysmic event through the destruction of ancient Earth, catapulting into the stars, relieved to be alive. As the closing titles roll, the film depicts Earth's evolution from that moment onward, illustrating the passage from ice ages until today, a testament to their survival and bond.
