A series of violent undersea earthquakes are causing large amounts of underwater volcanoes to appear in the Pacific Ocean depths, and this prompts the Calico to investigate. Traveling inside one of the volcanoes, the crew is menaced by a herd of large fire breathing reptiles who appear to thrive on the molten lava within. Godzilla is called to free the crew from the volcano, but another earthquake opens a fissure in the Earth that traps the Kaiju King deep within the planet's crust undersea.

Meanwhile, the crew manages to evade the fire lizards and discover the source of the earthquakes, a fallen Jupiter Probe rocket, which has become imbedded within two coastal tectonic plates. Going aboard the rocket, the crew attempts to utilize it to return to the surface, but are unable to activate its damaged engines. Godzilla finally bursts free from the earth's crust and enters the volcano in time to save Godzooky from the fire lizards. The Big G then brings the rocket containing the Cali