Planet of the Apes Wiki

Tern was a human taken in by the Ape City orangutan Doctor Cato and his assistant Prisca, who taught him sign language. After Councilor Tenebris organised the murder of Doctor Cato, Tern communicated to Prisca who was responsible. Tern ultimately killed Tenebris after Cato's friend General Aleron found himself unable to, but both Tern and Aleron were then swept downriver and assumed dead.

Two years later, Aleron and Tern had settled just inside the city ruins in the Forbidden Zone, and there organised a rag-tag community of humans who planned to assert their rights. Prisca was under suspicion when the humans began to raid ape villages, and with the help of Doctor Milo made her way to Aleron's camp. The sympathetic chimp Timon eventually betrayed Aleron to Dr. Zaius and guided an ape army to the secret lair. Zaius' army wiped out most of the humans, with Tern and his family escaping on rafts, but Aleron died destroying the passageway that led to the Forbidden Zone.