In the aftermath of a powerful storm, rescue and recovery teams are cleaning up Kurata Beach on Iwa Island. Reporter Ichiro Sakai and photographer Junko Nakanishi and discover an unusual blob floating among the debris. Meanwhile, at another beach, a mammoth egg is floating offshore and a team of fishermen is sent to pull it onto the beach.
Professor Miura examines the egg, which is at least three stories tall, trying to shrug off questions from Sakai. Self-described “Great Entrepreneur” Kumayama orders Miura to leave the egg alone, since he purchased it from the islanders and plans on exploiting it for financial gain. Later at the hotel, Junko, and Muira are discussing the sale of the egg, and Muira says there’s nothing that can be done. They spot Kumayama entering the hotel and follow him to a room. The businessman turns over the contract for the egg over to Shiro Torahata, the president of Happy Enterprises, who unveils plans for a tourism center featuring the egg, where they will easily make at least “a billion dollars!” They are interrupted by the Shobijin, two young girls about a foot tall, who plead for the egg to be returned. They try to capture the Fairy Twins, but they manage to escape. Sakai enters the room, mistaking the rowdy search for the tiny girls for a fight.
Sakai meets Muira and Junko in a glen near the hotel, where he tells them he overheard the plans by Torahata and Kumayama. The twins approach the newspaper people and the scientist, and ask them to return the egg to Mothra Island. The island had changed dramatically for the worse as a result of nearby nuclear testing. A recent hurricane had caused the egg to wash away. The fairies advise the three that if the egg hatches the creature inside could cause “great damage” while foraging for food. Mothra, also known as “The Thing” also wants the egg returned. The reporters and the scientist are surprised to find a giant moth in the brush behind them.
At the construction site, Sakai, Junko, and Muira are trying to convince Kumayama and Torahata to turn the egg over to the islanders. The two businessmen will hear nothing of it, until they see the Shobijin, who are being carried in an ornate case. The girls again plead for the return of the egg, but instead the entrepreneurs offer to buy the girls to include them as part of the tourist attraction. The reporters and the scientist leave, taking the twins with them. Back at the hotel, Sakai promises to write a negative story about the business venture, but admits public opinion is powerless against the law. The Shobijin slip away. The three return to the glen, just in time to watch Mothra and the twins fly off.
The villagers who sold the egg are demanding payment in full for the remainder of the contract that has not yet been paid. Kumayama calls Torahata and advises him about the villagers’ demands. Torahata is willing to loan Kumayama the money the villagers demand if he uses his share of the company as collateral to secure the loan. Kumayama reluctantly agrees. Sakai is frustrated with the public ambivalence to his articles about the egg. Editor Arota pushes Sakai to try harder and be more compelling. Arota receives a newstip that Kumayama is trying to hatch the egg. Junko rushes in and tells Sakai that Muira needs to see him urgently.
Muira decontaminates Sakai and Junko, who are both radioactive. He tells them the mysterious blob they discovered following the storm is also radioactive. They return to the beach which has since been drained of floodwaters, to test for radioactivity. Junko has been trying to take a picture of the property, but the land has been moving. The ground heaves, and steam is released from underground. The Geiger counter ticks madly. A giant tail emerges from the ground, followed by the rest of Godzilla. He shakes off the dirt and walks off toward Nagoya.
In the industrial sector, Godzilla crashes through oil pipelines and belches his terrible atomic fire. An army of fire trucks heads to the fires as residents try to evacuate. Looking behind them in panic, they watch the beast pull down a giant tower. As he continues through Nagoya, he trips and falls onto a pagoda, wrecking it as he tries regain his footing. U.S. military officials conferring with Japanese officials say they will use the Frontier Missile, “the newest and most powerful rockets the unit has ever developed.” U.S. warships offshore try to contain Godzilla to a beach using the missiles. Godzilla is temporarily stunned, but gets up again to continue his rampage.
Muira, Sakai and Junko are sent to Mothra Island to ask for the creature’s help in defeating Godzilla. Because of the devastation to their island caused by nuclear testing, the islanders and the twins are hesitant to implore the Thing to help them. But Junko and Sakai appeal to their humanity and compassion. The Shobijin appeal to Mothra to assist, who agrees. But Mothra is dying and will not return. However, a new Mothra will be hatched from the giant egg.
Kumayama attacks Torahata, wanting his money back because the tourist attraction has failed. Pulling money out of the safe, Kumayama is shot in the back by Torahata. As Torahata tries to escape from the hotel, he is killed when Godzilla tears down the building. Godzilla smashes the egg’s incubator, causing the egg to roll away. Mothra shows up to protect the egg and the people of Japan, and uses a yellow dust to disable Godzilla. As he writhes on the ground, he blasts Mothra with his nuclear fire, mortally injuring the flying creature. Mothra manages to make her way to the egg to die.
With Mothra dead, Japanese Defense Forces attempt an attack on Godzilla. A line of electrical towers are powered up as the beast approaches. The “artificial lightning” serves only to annoy him, and he pulls some of the towers down. As the Shobijin sing to the egg, Godzilla struggles as he is trapped by nets and is zapped with more “lightning.” The high voltage overloads the system, shuts it down, and melts the towers, allowing Godzilla to escape his bonds.
The egg hatches! Two Mothra larvae emerge! They follow Godzilla as to Iwa Island. The larvae spin a cocoon onto Godzilla. He becomes fully cocooned by the spray and falls into the ocean. The larvae swim off to Mothra Island.
Human Cast: Akira Takarada (Sirou Sakai), Yuriko Hoshi (Junko Nakanashi), Hiroshi Koizumi (Dr. Miura), Yu Fujiki (Jirou Nakamura), Kenji Sahara (Jirou Torahata), Emi Ito (Shojibin), Yumi Ito (Shojibin), Yoshihumi Tajima (Kumayama)
Monster Cast: Godzilla, The Thing (Mothra), Mothra Larvae
Notes: This is the U.S. version of Godzilla Vs. The Thing. The movie was originally released in Japan as Mothra Vs. Godzilla in 1964. The Frontier Missile scene does not exist in the original Japanese language Mothra Vs. Godzilla; instead, Japanese audiences saw a scene of military officials laying plans and issuing orders for an attack on the approaching Godzilla.
LogBook entry by Robert Parson