Susan Stevenson (Ursula Andress) is trying to find her missing anthropologist husband Henry in the jungles of New Guinea. She and her brother Arthur enlist the services of Professor Edward Foster (Stacy Keach), who thinks her husband might have headed for the mountain Ra Ra Me, which is located just off the coast on the island of Roka. The locals believe that the mountain is cursed, and the authorities won't allow expeditions there. So they surreptitiously head on into the jungle to see if that's where he went. They eventually make it to the island, and after a few run-ins against some unfriendly anacondas, alligators and tarantulas, they meet another jungle explorer named Manolo (Claudio Cassinelli) who's been staying at a nearby mission camp, and agrees to join them in their expedition. Matters become complicated when it then turns out that each of them has their own private reasons for coming to the island, and finding Susan's husband wasn't part of any of them. Susan and Arthur have secretly been looking for uranium deposits, and then Foster reveals that he has only come there because he had been on the island a few years previously and was taken captive by a tribe of primitive cannibals; he has only returned to see if they still exist, and wipe them out. However, Foster later dies when climbing up a waterfall. Upon arriving at the mountain, Arthur is killed and Manolo and Susan are immediately captured by cannibals and taken to their camp. There they find the primitives worshipping the remains of Susan's husband as they can hear his Geiger counter ticking, and believe it to be his heart still working. Susan is subsequently spared, while the cannibals feast on human and reptile flesh. She is stripped naked, tied up, and smeared with an orange cream by two native girls for what is supposed to be a session of honey torture, but she is instead turned into a goddess. Manolo is tied up and tortured, while the others are turned into the dish-of-the-day. Manolo and Susan eventually escape after enduring the ordeal.
