When Yuriko investigates increased volcanic activity in the Mt. Fuji area, she learns the story of a modern-day Tarzan named Takeru, who is rumored to live in the region's dense woods since becoming lost within them 15 years ago. Meanwhile underground volcanic energy creates boiling temperatures in a lake at the foot of the mountain and a huge boulder erupts from the waters. Because the rock obstructs a main travel route, it is blasted apart with dynamite and the pieces are transported back into the forest. At one night, the pieces collect around a strange luminescent rock, creating an enormous rock monster called Gorgos that lives and breathes like an animal.

Yuriko and Ippei are passangers on the inaugural voyage of the Inazuma; a futuristic bullet train leaving New Tokyo Station for North Kyushu. Mistaking it for Yuriko's case, Ippei accidently brings along the high-pressure container which houses Dr. Aikawa's artifical lifeforrn, M1.

Jun, Ippei and Yuriko investigate a hillside accident involving a truck that was transporting a uranium capsule. After rescuing the drivers, they learn that the monster Pagos had surfaced from underground, following the appearance of a mysterious rainbow, and caused the accident.

Following the sighting of a UFO and the destruction of two J.S.D.F jets sent to investigate, a series of strange disappearances plagues Tokyo. When Yuriko witnesses a woman vanish before her eyes, she begins her own investigation.