Charlize Theron takes on the role of Jill Young, a character whose tragic past includes witnessing the shocking murder of her mother. Alongside her, a baby ape named Joe has also endured great loss; they both suffered at the hands of ruthless poachers led by the brutal Andrei Strasser (played by Rade Serbedzija). In a moment that changes everything, Joe protects himself and earns a place in Jill’s heart by inflicting a significant injury on Strasser. Fast forward twelve years, and Jill has lovingly raised the now large Joe, who faces rejection from other gorillas due to his size.

Their unique bond thrives in isolation until their peaceful existence is disrupted by Gregg O’Hara, portrayed by Bill Paxton, a dedicated director of a wildlife refuge. He suggests that relocating to the United States could provide a safer haven away from lurking poachers. As they make their way to the vibrant streets of Hollywood, California, they capture the affection of the refuge staff but soon attract the attention of Strasser, who, driven by vengeance for the injury he sustained years earlier, seeks to reclaim his power.

Despite Jill’s unawareness of Strasser’s nefarious background, she finds herself being manipulated by him as he plays on her emotions, suggesting that returning Joe to his origins in Africa may be the best solution. At a glamorous gala, tensions escalate when Strasser’s henchman employs a poacher’s noisemaker to incite panic in Joe. In an unexpected frenzy, Joe wreaks havoc at the event and finally recognizes Strasser, prompting a desperate attempt to attack him. The situation takes a dark turn when Joe is tranquilized and confined to a bleak concrete bunker, leading Jill to the painful realization that her companion’s life hangs in the balance, with euthanasia looming on the horizon.

In a drastic move, Jill accepts Strasser’s manipulative offer, but during their flight to the airport, a shocking revelation strikes her when she recognizes Strasser’s telltale missing fingers. A burst of adrenaline compels her to crash the truck, allowing Joe the chance to escape. As fate intertwines their paths, Gregg also becomes aware of Strasser’s true identity and rushes to aid Jill and Joe. Their journey culminates at a carnival where Strasser recklessly attempts to eliminate Jill, inadvertently igniting a fire that leads to a catastrophic collapse of the Ferris wheel.

In a heart-wrenching scene reminiscent of King Kong’s fateful descent, Joe heroically saves a child but succumbs to the chaos, falling from the wreckage. However, he survives this harrowing encounter and, in a gesture of newfound freedom, returns to Africa, where he can roam free in a refuge supported by his newfound fans, allowing both him and Jill to finally find peace in their separate yet intertwined destinies.