In this vivid view of prehistoric life, a man from the mean-spirited Rock People (John Richardson) is banished from his home. He soon finds himself among the kind, gentle Shell People and falls in love with one of their loving tribeswomen (Raquel Welch). The twosome decide to face the world together, cut off from all tribal support, alone in a deadly world of hideous beasts and earth-shattering volcanic eruptions. The film's pioneering special effects have made it a true science-fiction classic.