The rift between the Chimps and the Orangutans escalates. Cornelius is at a meeting where a human female, Pin, is telling them that "Timon will show us the way", which ties this directly to Boom's Exile on the Planet of the Apes series. Timon tells the story of the one-eyed gorilla Aleron and how he created a utopia for apes and humans in the Forbidden Zone, which is a bit of an exaggeration. Meanwhile, Dr. Zaius believes that Ape Society is crumbling because of all of this discontent. He meets with Marcus, the head gorilla, and they talk about this false religion. Then, he confronts Timon and tells him to pack it up and go away. The relationship between Cornelius and Zira also grows. Everything escalates when the gorilla army goes to the Chimpanzee Refugee camp and violence erupts.
This takes place five years before the events of the first PLANET OF THE APES movie and does an excellent job of telling the backstory to that landmark film.