Following the downfall of civilization a small tribal group huddles in a cave. Sex has been banned by the elders in order to keep population numbers down. David leads a group of teenagers in teaching them to read. He kills the tribal shaman when the shaman tries to take David’s girlfriend Sarah into his bed. He then leads the rest of the group into the wilderness. They become lost in a storm, but come around in the sanctuary of Neil and his girlfriend Judith. There Neil introduces them to alcohol, drugs and sex. But they soon discover that Neil and Judith are the results of genetic experimentation and both are over a hundred years old and invulnerable to almost all damage. But when Neil has sex with the girls he causes them to be impregnated with his own genetic material and explode