Demetrios is a Greek fisherman who, with his father, rescues Princess Antillia from a shipwreck, only to discover she hails from the technologically advanced realm of Atlantis. Their voyage carries them beyond the Pillars of Hercules to return Antillia home, but fate takes a dark turn when a giant fish-like submarine drags them toward an empire that is about to implode. Demetrios, expecting a reward for his help, is captured instead and forced to labor in the crater of a volcano that dominates the continent.
In Atlantis, King Kronas is maneuvered by an ambitious usurper, Zaren, who collaborates with the court sorcerer, Sonoy the Astrologer, to bend Atlantis’s power to their own conquest of the known world. From deep within the volcano, slaves mine rare power crystals that drink in the sun’s rays and can be shaped into heat-ray beams. These crystals were once used for light and warmth, but pride, corruption, and moral laxity have turned them into a weapon of terrifying potential. It has become > "an abomination before Heaven".
Demetrios is taken to the House of Fear, where a mad scientist turns slaves into mindless beasts. He earns his freedom by undertaking the ordeal of fire and water, a brutal test in which he faces a giant ogre in a pit of roaring coals. The crowd’s laughter and the clash of fire and water amplify the drama, but Demetrios outmaneuvers the hulking foe and, after a tense ascent through a rising pool, he defeats the ogre and is named a free citizen of Atlantis.
Doom hangs heavy over the city as signs of catastrophe multiply. With the crucial aid of the kindly high-priest, Azor the High Priest, Demetrios learns to read the omens and the looming apocalypse. Azor explains the two small versions of the crystal device and warns that a far larger crystal ray projector—central to Atlantis’s power—will soon be ready. When the full moon rises, Zaren intends to launch a swift campaign of conquest.
To stop him, Demetrios pretends to rally with Zaren among the slaves, all the while secretly sabotaging the construction. The crystals form deep within the volcano, accelerating Atlantis’s own descent toward ruin.
On the night of the full moon, the completed crystal ray projector is unveiled to the people. Dark skies roll in, the ground trembles, and the continent starts to tear itself apart. Zaren makes a desperate bid to eliminate Demetrios and Antillia with the weapon, but the weapon backfires, killing Zaren as Azor’s blade clashes with the rogue plot. The crystal’s energy spirals out of control, and the capital’s beacon explodes as the giant pyramid’s power core is flooded and short-circuits.
As Atlantis sinks beneath the waves, the sea floor collapses, and the continent vanishes. Survivors, including Demetrios and Antillia, escape to Greece and other corners of the world, where they blend into new cultures and their extraordinary tale becomes the seed of the Atlantis legend that endures through the ages.
