Scientists observe a tribe, which lives peacefully outside the external world in the rainforest. Theyknow no form of writing and communicate only with their simple dances. After some month ofabstinence, the scientists visit the tribe again and discover, that their whole behavior has changedcompletely. They pray to a skull-god and menace the scientist. Now they use weird signs, whichthey paint on themselves. The scientists have to find out what happened.