Athena-1, a space station owned by gene-manipulation company Energyne, is destroyed after a laboratory rat mutates and wreaks havoc. Kerry Atkins, the lone surviving crew member, manages to escape in the escape pod when the station implodes, along with pathogen canisters that Energyne CEO Claire Wyden orders her to retrieve, but the pod disintegrates upon re-entry, killing her and leaving a trail of debris across the United States. One canister is swallowed by an American crocodile in the Everglades and another lands in a Wyoming forest where a wolf is exposed to the pathogen.
Primatologist Davis Okoye, a former US Army Special Forces soldier and member of an anti-poaching unit, works at the San Diego Wildlife Sanctuary. He has befriended a rare albino western lowland gorilla named George that he saved from poachers who killed his mother and communicates with him via sign language. One of the canisters crash-lands in George’s habitat and he is exposed to the pathogen.
As George grows considerably larger and more aggressive, Davis is contacted by genetic engineer Doctor Kate Caldwell, who explains that the pathogen was developed by Energyne to rewrite genes on a massive scale. She had hoped to advance research on CRISPR as a potential cure for diseases, but discovered Energyne’s plans to use it as a biological weapon and was falsely incarcerated, during which her terminally ill brother died. George escapes from captivity and goes on a rampage at the preserve. George is calmed, but is soon captured by a government team led by Agent Harvey Russell and put on a Boeing C-17 Globemaster III airplane. Meanwhile, Claire and her brother Brett oversee a mercenary team’s attempt to capture the mutated wolf, Ralph, which ends in failure and the slaughter of the entire team.