يتبع الجهود البطولية التي تبذلها وكالة علم الحيوان المشفرة Monarch حيث يواجه أعضاؤها مجموعة من الوحوش ذات الحجم الإلهي ، بما في ذلك Godzilla الأقوياء ، الذين يصطدمون بموثرا ورودان وعدوه النهائي ، الملك غيدوراه ذي الرؤوس الثلاثة. عندما ظهرت هذه الأنواع الفائقة القديمة ، التي يُعتقد أنها مجرد أساطير ، مرة أخرى ، فإنها تتنافس جميعًا على السيادة ، تاركة وجود البشرية ذاته معلقًا في الميزان.

Humanity finally rids themselves of Godzilla, imprisoning him in an icy tomb in the South Pole. All is peaceful until various monsters emerge to lay waste to Earth's cities. Overwhelmed, humanity is seemingly saved by a race of benevolent aliens known as Xiliens. But not all is what it seems with these bizarre visitors. If humanity wishes to survive, they must reluctantly resurrect their most hated enemy, Godzilla.

Astronauts Glenn and Fuji investigate Planet X and encounter mysterious aliens known as the Xiliens, who ask Earth's people to help save their world from "Monster Zero". In exchange for borrowing Godzilla and Rodan, the Xiliens offer a cure for cancer. As Glenn investigates, he develops a romance with Miss Namikawa and uncovers the Xilien's true intentions.

At the turn of the century, all of the Earth's monsters have been rounded up and kept safely on Monsterland. Chaos erupts when a race of she-aliens known as the Kilaaks unleash the monsters across the world.