George Taylor and his crew of astronauts were on a simple mission: travel into the future of the galaxy and see if there really was any other intelligent life out there. Upon awaking from deep-sleep, the astronauts find themselves on an alien planet ruled by intelligent apes and man is the beast of burden. Asserting himself as a superior human due to his ability to speak, Taylor has made himself a target. Fleeing from the Ape City with a pair of curious apes in tow, he makes his way towards the "Forbidden Zone", a holy place for the apes which is supposed to hold their history and conquest over man...