Manga artist Gengo Odaka lands a job with the World Children's Land amusement park only to become suspicious of the organization when a garbled message is discovered on tapes. As Gengo and his team investigate, Godzilla and Anguirus quickly decipher the message and begin their own plan of action.
When a space probe crash-lands on a far-flung Pacific atoll, the craft's alien stowaways decide to take over their new world one creature at a time. Soon, the parasitic life forms latch onto three indigenous critters -- a squid, a crab and a snapping turtle -- and transform them into colossal mutant monsters.
A food company president is promoted to chairman, but his continued involvement creates leadership confusion.
