Gerrilla (Lorraine De Selle), an anthropologist living in New York, and his brother Rudy (Danilo Mattei) and good friend Pat (Zora Kerova) go to the Amazon jungle to investigate the customs of the natives. After arriving at their destination, they meet two drug dealers hiding from the outside world: Mike (Giovanni Lombardo Radice) and Joe (Walter Lucchini). These two evil guys used the locals to help them engage in drug production and trade, and beat and scolded the locals if they were not happy. As the saying goes, evil is full of evil, and good and evil are rewarded. Mike aroused the anger of this group of kind people by brutally killing locals, including the daughters of indigenous leaders. They took up arms and retaliated against the invading whites, and Grace was implicated.