|Return to the Planet of the Apes|
|Episode||Trail to the Unknown|
|Air Date||November 1, 1975|
| Previous Episode: "Screaming Wings"
Next Episode: "Attack from the Clouds"
Bill, Jeff and Judy begin building rafts to help the human tribe reach New Valley on the river and escape Urko's patrols. In Ape City, Dr. Zaius visits Cornelius and Zira in their lab to thank them for stealing Urko's plane. By doing so, he feels that they have saved simian society from Urko's dictatorship. They assure him that they had nothing to do with the stolen plane, but Zaius insists that their secret is safe with him. He leaves them with the news that Urko has been given permission to attack the human caves to find 'Blue Eyes'.
Finally the rafts are finished and Bill and the others begin the long journey towards New Valley, following the map given to them by Cornelius. The trip takes them through thick jungle growth and swarms of bats. Some of the humans get sick and want to turn back, but Bill decides that they have no choice but to press on. By nightfall, the jungle has given way to a desolate, desert area. Meanwhile, Urko is still enraged over the theft of his plane and orders it found. Since the plane was a military secret, he suspects someone on the inside to be responsible. Urko offers a reward for the thieves' capture and orders the attack on the humans to begin at dawn.
Following their map, Bill, Jeff and Judy lead the humans from the rafts across the desert. Despite the terrible heat and wind, they press on. When the army arrives at the river, Urko realizes that the chopped trees mean the humans escaped by raft. Furious that his men are not prepared for water travel, Urko returns to the city for the Council's approval for a water maneuver.
The next day, Bill and the others come upon an incredible sight: the wreck of a United States spaceship! A stranger appears and introduces himself as Col. Ron Brent. He tells them that he has been marooned here since Nova was a little girl. He left Earth on August 6, 2109 from a launch pad in the Mojave Desert. Cape Kennedy had been turned into a museum sixty years before he was born. After crashing, Nova's tribe helped nurse his broken leg. He decided to join in the tribe's travels, but was separated from them. He returned and made his crashed ship his headquarters for the past twenty years. Brent tells Bill that he knows the way to New Valley and will guide them there. Before leaving, he brings his ship's self-destruct mechanism.
Meanwhile, the Council has doubts about Urko 's ability to find the humans. The gorilla is granted permission to locate the humans, but a Council mandate is required before starting an attack. Finally, Bill and the others reach New Valley. They begin building a fortress using the ship's laser. Just as the fortress is finished, the army arrives. Urko plans to deceive the Council and attack the humans in "self defense." Their gas grenades won't penetrate the human's fortress. Urko can't believe the humans were smart enough to build defenses and is forced to return to the city for the heavier artillery. Figuring Urko will return, Bill decides to destroy the land bridge into the Valley with Brent's destruct mechanism. First however, they must get the plane.
- River of Flames, Screaming Wings and Trail to the Unknown were adapted as Return to the Planet of the Apes #3: Man, The Hunted Animal by 'William Arrow' (William Rostler), and published by Ballantine Books.
|Return to the Planet of the Apes|
|"Flames of Doom"||"Escape from Ape City"||"The Unearthly Prophecy"||"Tunnel of Fear"||"Lagoon of Peril"||"Terror on Ice Mountain"||"River of Flames"|
|"Screaming Wings"||"Trail to the Unknown"||"Attack from the Clouds"||"Mission of Mercy"||"Invasion of the Underdwellers"||"Battle of the Titans"||Return to the Planet of the Apes|