Agioupa, an unruly orphan girl, sleeps in the fields, choosing the company of the birds to her fellow villagers.

Lt. Andre Saint-Avit, an officer of the French Foreign Legion, is discovered unconscious in the Sahara Desert after three month's absence. While searching for a missing archaeologist in Algeria's Hoggar Mountains, he and his partner, Capt. Jean Morhange, had been captured and confined to the lost kingdom of Atlantis. Queen Antinea, its immortal ruler, had a penchant for taking a series of lovers. Later, when each falls out of her favor, she embalms and gold plates them to create ornamental statues. Sometime after his arrival, Andre is summoned by Antinea and seduced. He is totally blitzed with her. Eventually, when she tires of him, she next calls for his partner Jean. Jean seems able to resist her charms, but Andre does not know this. Antinea manages to make Andre think otherwise. In a fit of jealousy, Andre kills Jean and manages to flee. Although back home he confesses to his killing Jean, his superiors give his tale no credence. They acquit him. Then, a rider from Atlantis shows up at the fort bearing a familiar necklace.

A civilization of gorgeous cavewomen abduct men for mating purposes. One of their victims is Engor, who seems to be smarter than the rest of the men. He discovers fire, battles a monstrous giant and attempts to win the hand of the prehistoric queen.