The astronauts help a captured human perfect a glider while being studied by a scientist who is very interested in the secret of flight.
The astronauts are captured by a band of humans who are allowed to remain free only if they continue to supply the gorillas with human captives.
The astronauts make quinine for a malaria-devastated village.
The fugitives embark on a plan to remove a corrupt district chief from office.
A scientist tries ancient brainwashing techniques on captured Burke.
Virdon rides in a horse race for the life of a blacksmith's son.
A blind ape falls in love with Burke, not realizing he is a human.
Galen seeks the aid of his former fiancee, a surgeon at the Medical Center, when Virdon is shot by a gorilla patrol.
Virdon and Burke are captured and enslaved by the head of a fishing colony.
Virdon, Burke and Galen learn that a wealth of information about the past is buried somewhere in the ruins of a one-time city.
The astronauts are forced to take refuge at a farm run by a gorilla family when Galen is seriously injured in a fall.
While exploring the remains of San Francisco, an earthquake causes Burke to become trapped with Urko in an old subway tunnel.
Burke and Virdon happen upon a village where humans are trained to fight each other to the death -- gladiator style.
Two astronauts crash on an Earth of the future where apes rule and people are considered to be animals.