To save his insolvent circus, entrepreneur Mark Remington travels in search of the legendary Gorga, a 50-ton gorilla. Arriving in Africa, the American finds his contact, Bwana Jack, missing. After placating Jack's greedy associate Morgan, Remington, accompanied by Jack's daughter, April Adams, and foreman, George, sets out through the jungle. Deserted by native guides, the company encounters dinosaurs and Gorga, and is abducted by a hostile tribe. Their sacrifice, along with that of Jack, discovered to be a fellow prisoner, is interrupted by the reappearance of the gorilla. Fleeing their captors the four seek shelter in a cave, where they unearth a treasure and are menaced by a prehistoric beast. Upon emerging from the cave, George is slain by Morgan, who is himself killed by Gorga. Laden with treasure, the trio returns home.