Story
An Okinawan prophecy that foretells the destruction of the Earth is seeming fulfilled when Godzilla emerges to return to his destructive roots. But not all is what it seems after Godzilla breaks his ally Anguirus's jaw. Matters are further complicated when a second Godzilla emerges, revealing the doppelgänger as a mechanical weapon.
Screenplay
While covering a test of guided torpedoes, two reporters believe they see what appears to be a strange-looking swimming creature. They investigate the matter further and discover that there is a race of fish-men living under the sea. The fish-men capture the pair and keep them prisoner in their underwater city.
Adaptation
Five vacationers and two crewmen become stranded on a tropical island near the equator. The island has little edible food for them to use as they try to live in a fungus covered hulk while repairing Kessei's yacht. Eventually they struggle over the food rations which were left behind by the former crew. Soon they discover something unfriendly there...