This spectacular Prehistoric adventure tells the story of Tumak, a caveman and the son of the leader of the Rock Tribe. When Tumak (John Richardson) is banished from his tribe he wanders through the brutal prehistoric lands until he stumbles apon the Shell Tribe. Loana (Raquel Welch), the daughter of the chief, takes pity on the exhausted and injured wanderer and nurses him back to health, much to the chagrin of her betroved, who fights Tumak for his honour and the hand of his woman. Tumak is expelled as a result. Again he has to wander the treacherous wastelands in search of his tribe. Loana decides to join him and follows him back to the caves of his people. She teaches the Rock tribe civility and Tumak assumes leadership. The tribe seems as peace, though this peace is shattered by Tumak's treacherous brother Sakana (Percy Herbert) who plots to overthrow the new chief.