Terror of Mechagodzilla

Interpol agents dive to the bottom of the Okinawan Sea to recover Mechagodzilla's wreckage and to gather information about the Simeons. The mission follows the earlier battles between Godzilla, King Caesar, and the defeated Mechagodzilla. The undersea search is tense, with every clue potentially reshaping humanity's fate.

Their submarine is attacked by a gigantic marine dinosaur they name Titanosaurus. The crew vanishes in the assault, leaving Interpol with a chilling mystery and no clear exit strategy.

Interpol initiates an investigation into the Titanosaurus incident and Mechagodzilla's remnants. They recruit marine biologist Akira Ichinose to help trace Titanosaurus to the reclusive scientist Mafune.

The team visits Mafune's secluded home and meets his daughter Katsura, who has secretly become a cyborg after a lab accident. Katsura claims Mafune is dead and says she burned his notes about Titanosaurus.

Tsuda, an aide to Simeon leader Mugal, visits Mafune to propose an alliance to rebuild Mechagodzilla 2 and help wipe out mankind. Mafune weighs the offer, seeing potential to advance his own plans.

A control device for Mechagodzilla 2 is implanted into Katsura, enabling Mafune and the Simeons to remotely command the monster. The procedure ties Katsura to their scheme and amplifies the danger of their collaboration.

Ichinose falls in love with Katsura, and in a fateful turn he unwittingly shares Interpol's information about the Simeons, Mechagodzilla, and Titanosaurus with her. The trust between the agencies and Mafune's circle begins to blur, complicating the pursuit.

In a rash move, Mafune unleashes Titanosaurus on Yokosuka without waiting for the Simeons' permission. The monster causes chaos and proves difficult to control, underscoring Mafune's reckless ambition.

Interpol discovers Titanosaurus is vulnerable to supersonic waves. Katsura destroys Interpol's supersonic wave oscillator to prevent countermeasures from working.

Godzilla arrives and easily defeats Titanosaurus, forcing the creature to retreat from Yokosuka. The immediate threat shifts toward Mechagodzilla and the Simeons' larger plot.

Ichinose visits Katsura, but the Simeons capture him and unleash Mechagodzilla 2 and Titanosaurus on Tokyo. The city becomes the focal point of the escalating monster assault.

Interpol repairs their wave oscillator, allowing the Japanese forces to counter Titanosaurus. Godzilla fights Mechagodzilla 2 while Titanosaurus remains a major obstacle.

Interpol agents infiltrate the Simeons' hideout, rescue Ichinose, and kill Mafune and many Simeons. The remaining Simeons scramble to escape as the net tightens.

The wounded Katsura shoots herself to disable Mechagodzilla 2's control device. Godzilla destroys Mechagodzilla 2 amid the chaos, and Katsura dies in Ichinose's arms.

With help from Interpol, Godzilla defeats Titanosaurus and returns to the ocean. The battle ends and the world begins to recover from the devastation.