Screenplay written by Kaoru Mabuchi

A wild boy is discovered haunting the streets of Hiroshima by scientists Dr. Bowen, Dr. Kawachi and Dr. Sueko. The creature turns out to be the revived Frankenstein monster, regrown from a desicated heart by the Atomic Bomb's radiation. Frankenstein grows in size and cunning, hunting livestock and pets for food. Because Frankenstein eats meat, the JSDF is worried that the monster will turn to consuming human beings.

Meanwhile, Godzilla is discovered trapped in ice in the Bering Sea. It is decided to free Godzilla and lure the monster back to Japan, where he will hopefully fight and kill Frankenstein's monster. Ships lure Godzilla to the coast, from which a series of towers with light beacons draw the atomic dragon to the area of Mt. Fuji.

Godzilla menaces Dr. Sueko, but Frankenstein saves her from the reptile. Frankenstein begins a hit and run type of battle with Godzilla, striking the dinosaur, then retreating back into Fuji forest. At last, a volcanic fissure opens up, swallowing Frankenstein. Godzilla is knocked backwards into a raging river, and is swept away by the current, his final fate unknown.

History:

Toho had long desired to produce a film with Frankenstein's monster. Their first effort was a Shinichi Sekizawa screenplay from 1963 entitled Frankenstein vs the Human Vapor, a sequel to their sci-fi film The Human Vapor. In this treatment, the Vapor Man returns, seeking out mad scientist Dr. Gildor who has stolen the body of the Frankenstein monster from the Frankenstein family cemetery in Germany. Gildor brings the monster back to life in his Hong Kong lab, but news of this event brings Mizuno, the Vapor Man to the scientist's door. Mizuno hopes Gildor can bring his slain lover back from the grave. Sadly, this is as far as the Sekizawa script advanced, leaving the rest of the story pure speculation.

Toho's next idea was to employ a larger Frankenstein monster against their own monster star, Godzilla. The result was a signifigantly flawed script from Kaoru Mabuchi. At this time Godzilla had not yet made the jump from villain to hero, and would have emerged as the greater of two evils over the course of the film. In the end, Godzilla was removed from the script and the new monster Baragon was substituted, resulting in 'Frankenstein vs the Underground Monster Baragon' - Frankenstein Conquers the World.