After conquering the oppressive humans in "Conquest for the Planet of the Apes", Caesar must now keep the peace among the humans and apes. Gorilla General Aldo views things differently, and tries to cause an ape civil war. In the meantime, other human survivors learn of the ape city, and decide they want to take back civilization for themselves, thus setting the stage of warring ape factions and humans.

Following the events in "Beneath the Planet of the Apes", Cornelius and Zira flee back through time to 20th Century Los Angeles, where they face fear and persecution similar to what Taylor and Brent suffered in the future, and discover the origins of the stream of events that will shape their world. Written by Marg Baskin

Brent is an American astronaut, part of a team sent to locate missing fellow American astronaut, George Taylor. Following Taylor's known flight trajectory, the search and rescue team crash lands on an unknown planet much like Earth in the year 3955, with Brent being the only survivor of the team. What Brent initially does not know, much like Taylor didn't initially know when he landed here before Brent, is that he has landed back on Earth in the future, in the vicinity of what was New York City....