Gli astronauti Virdon e Burke si imbattono in un fenomeno spaziale e si ritrovano sulla Terra, ma nel 3085. Ora la specie dominante sull'intero pianeta è quella delle scimmie.

Burke e Virdon sono costretti a combattere all'ultimo sangue dopo essere stati catturati da una scimmia Prefetto che organizza lotte di gladiatori fra gli umani.

Burke e il generale Urko sono costretti a lavorare insieme quando si ritrovano seppelliti vivi in una vecchia stazione della metropolitana di San Francisco a seguito di un terremoto.

Burke and Virdon have to seek the help of a gorilla farmer and his family when Galen falls sick.

Burke and Virdon are helped by a young woman and a young boy while searching for an underground computer in a ruined city, but their plans go awry when Alan is captured and Urko uses the boy to get information from the astronaut.

An ape who runs a fishing business plans to use Virdon and Burke as slaves after he captures them.

Galen must use all his charm to try and persuade his ex-girlfriend, a female ape surgeon named Kira, to operate on Virdon using a forbidden human anatomy book, after the astronaut is shot.

When the guys try to track down the apes who are framing humans for crimes in a small community, Fauna, a blind female ape, falls in love with Burke while believing him to be a chimpanzee.

Virdon decides to take part in a dangerous horse race even though he runs the risk of being captured by Urko.

Burke undergoes a horrific interrogation after being captured whilst Virdon and Galen mount a rescue attempt.

Aboro, a despot, is making community life a misery; Burke, Virdon, and Galen decide to rob him of his powers.

Thanks to their advanced medical knowledge, Burke and Virdon are able to help a village struck with malaria, but risk discovery.

Burke and Virdon are captured by a bunch of humans determined to hand them over to the Apes.

Burke and Virdon join forces with Leuric, a human attempting to fly by building himself a hang glider.