Biography of boxer Marcel Cerdan.; A young boy, interested in continuing his father's work on the Neanderthal Man, must deal with an unjust guardian who has anything but the boy's interests at heart. The young man, considered a weakling, personally researches primative man's mystic ritual of strength, and meets Rok-ta, who turns him into "A Man of the Caves": a primative himself! He kills his guardian, but then he meets the Heap!