When a young fisherman in ancient Greece rescues a princess, she entices him to travel with her to her fabled home, The Lost Continent of Atlantis. There, Demetrios (Anthony Hall) is enslaved by an evil tyrant bent on using the Atlantean's technology to dominate the earth. But winning his freedom through combat, Demetrios flees with Princess Antilla (Joyce Taylor) just as the lava from an exploding volcano causes the Atlantean's weapon to explode in a cataclysm that destroys a continent. Safely away, Demetrios and Antilla watch her home sink below the ocean to be lost forever.