Comic book artist Gengo Kotaka is engaged by World Children’s Land to assist in developing a theme park in Japan, featuring a tower shaped like Godzilla. As he reports to work one day, he is nearly knocked over by a woman running out of the building, who is being chased by several men. She drops an audio tape as she dashes off. Inside, he meets the chairman of the Japanese branch of World Children’s Land. The Chairman tells Gengo that the woman is an “enemy of peace.”
Returning home, Gengo is mugged by the woman and one of her cohorts, who demand the tape. They tell Gengo that Children’s Land is the real enemy of peace, based on journals left by Machiko’s missing brother. Gengo accepts their story, and leads them to a locker in which he had hidden the tape. They play back the tape, which emits a strange sound. At the Godzilla tower, the Chairman and his henchmen pick up the sound, the “Action Signal.” It’s also heard by Godzilla and Anguirus at Monster Island. The King of the Monsters dispatches Anguirus to investigate the mysterious sound.
Gengo and his new friends conduct background checks on World Children’s Land and the Chairman, only to find many irregularities. The most surprising is that the Chairman died a year ago. Apparently, the Chairman and the others are taking over the bodies of recently deceased humans. Back at the tower, the Chairman receives a message from Nebula Space Hunter M in preparation of an invasion. He orders the playing of “Action Signal 1.” Just then, Anguirus arrives at a nearby bay. The army swings into action, and is able to turn back the spiked monster.
Snooping around at the Godzilla Tower, Gengo finds Machiko’s brother. He is caught and run off, but followed by the chairman?s henchmen. Gengo, Machiko, and Shosaku are about to be killed, when Gengo’s sister arrives and beats them away. Meanwhile, Godzilla and Anguirus are making their way to Japan. At the same time another Action Signal is played, which calls space monsters Gigan and King Ghidorah. Gigan is a horned bipedal Cyclops-type creature with multiple fins on his back, hooks for hands and a buzzsaw in his abdomen.
Gengo and his sister attempt rescue Machiko’s brother from the Godzilla tower, but are captured by the aliens. One of the Chairman’s henchmen reveals they are the advance force for creatures from Nebula Space Hunter M, which has very nearly been destroyed by pollution. The aliens are in reality the only surviving race of that planet: giant cockroaches. Controlled by the aliens, Ghidorah and Gigan arrive on Earth. The monsters are ordered to attack Tokyo. The pair rip through the city as if it were simply model buildings.
Godzilla and Anguirus arrive. Gigan leaps into the air, but is brought down by a mighty blast of Godzilla?s nuclear breath. Godzilla is, in turn, felled by Ghidorah’s lightning bolts. But both Gigan and the King of the Monsters get up. Ghidorah sets the oil storage tanks afire, and Godzilla pulls Anguirus from the flames. Meanwhile, Machiko and Shosaku mount a rescue mission for their friends in the Godzilla tower. A weather balloon is floated to the imprisoned friends, who escape by sliding down a rope.
The battle between the kaiju continues and is moving closer to the theme park. Godzilla and Ghidorah wrestle while Gigan focuses his attentions on Anguirus. But Gigan leaps into the air toward Godzilla. The space monster uses the buzzsaw in his abdomen and slices a huge gash in Godzilla’s shoulder. Godzilla stumbles in pain into the theme park and is startled to find the tower shaped in his image. As he approaches the tower, the aliens shoot lasers from the tower at the monster, which knocked Godzilla off his feet.
A small task forced lead by Gengo carries explosives into the tower, since the interior is lightly defended. While they do so, the monster battle continues, with Gigan taking a slice out of Anguirus. Moments later, the explosives destroy the tower from inside. As it burns, the aliens revert to their original cockroach shape. The tower explodes, releasing the control the aliens held over space monsters.
Even without direction, Gigan and Ghidorah are able to put the other two monsters on the ropes. Godzilla is able to gather a second wind and manages to subdue Gigan. Ghidorah, which has been watching from the sidelines, is attacked by a rejuvenated Anguirus. The three headed monster however lifts the spiked beast into the air and drops him. Godzilla and Anguirus double-team the other monsters by having Anguirus jump backward onto the golden monster, which then collides into Gigan. Godzilla stomps onto one of the necks of Ghidorah, but the golden creature rolls free. Without leadership and facing the overwhelming force of Godzilla and Anguirus, the two space monsters flee.
Human Cast: Hiroshi Ishikawa (Gengo Kotaka), Tomoko Umeda (Machiko Shima), Yuriko Hishimi (Tomoko Tomoe), Minoru Takashima (Shosaku Takasugi)
Monster Cast: Godzilla, Gigan, King Ghidorah, Anguirus
Notes: Godzilla speaks! You’ll recall that in Ghidrah, The Three Headed Monster the Fairy Twins translate a discussion between Godzilla, Rodan, and Mothra. But here, Godzilla and Anguirus speak in English. The Japanese version reportedly uses comic book type balloons. Originally released in Japan as Earth Attack Command: Godzilla vs. Gigan.
LogBook entry by Robert Parson