Pete, Alan and Galen are stopped on the road by a gorilla patrol who do not recognise the outlaws. They tell the three that they are about to enter a restricted area and that the gorilla soldiers are not allowed to enter to protect Galen there. Intrigued, they move on and come to a human village with it's prefect's house deserted. The humans there allow Galen and his 'servants' to stay in the house and tell them that the last gorilla prefect left for Central City with a human named Cluf, but Cluf returned alone, with Urko's promise of independence for the human village. Rifle shots can be heard every night and Pete discovers Cluf shooting at a target. When they hear that Zaius and Urko are to visit the experimental village, they suddenly realise Urko's master-plan: he has payed Cluf to shoot Zaius, and with this publicity Urko will take over the government and crush all the humans. They stop Cluf just in time and save Zaius' life. As Urko's gorillas arrive to take away Cluf, the three take to the road again.