Caesar and his apes are forced into a deadly conflict with an army of humans led by a ruthless Colonel. After the apes suffer unimaginable losses, Caesar wrestles with his darker instincts and begins his own mythic quest to avenge his kind. As the journey finally brings them face to face, Caesar and the Colonel are pitted against each other in an epic battle that will determine the fate of both their species and the future of the planet.

On the brink of the First World War, Albert's beloved horse Joey is sold to the Cavalry by his father. Against the backdrop of the Great War, Joey begins an odyssey full of danger, joy, and sorrow, and he transforms everyone he meets along the way. Meanwhile, Albert, unable to forget his equine friend, searches the battlefields of France to find Joey and bring him home.

A group of scientists in San Francisco struggle to stay alive in the aftermath of a plague that is wiping out humanity, while Caesar tries to maintain dominance over his community of intelligent apes.