The ''Helios 7'' space probe is sent on a mission to study the planet Jupiter. While on its outward journey to the gas giant, the probe is overtaken by the Space Amoeba, an amorphous parasitic extraterrestrial. The probe returns to Earth and crashes into the South Pacific, where the Amoeba leaves the device and inhabits the body of a cuttlefish, causing it to mutate into what is called "Gezora". The tentacled kaiju begins attacking ships and islands in the area.