Roddy McDowall returns as Caesar, the intelligent chimp who led an ape revolution against their human masters in the last installment, Conquest of the Planet of the Apes. Since then, humans nearly rendered themselves extinct in an all-out nuclear war, and the survivors are now beneath the well-preserved ape society. Now a benevolent leader of his people, Caesar supports a peaceful coexistence with humans, much to the dismay of his militant counterpart General Aldo (Claude Akins). When Caesar learns that new evidence regarding his parents' murder has been found in the Forbidden City, he journeys to the bombarded wasteland with the human MacDonald (Austin Stoker) and the omniscient orangutan Virgil (Paul Williams). While he does find what he is looking for, Caesar also unwittingly awakens a flock of human survivors, who follows his group back home.