As a long dormant volcano in Alaska suddenly erupts, the crew of the Calico decides to investigate the phenomena. Suddenly, an enormous winged creature called the Firebird, since she literally thrives in super-heated lava and breathes fire, emerges from her resting place in the volcano (there is actually a legendary avian creature by that name in Russian mythology, though this fact is not alluded to in the show). The Firebird flies across the frozen Arctic Sea to find a place to spawn, the heat from her body causing huge floods as her very proximity melts glaciers. Godzilla is called to the rescue by his human friends, and after a fierce battle, he defeats the Firebird by trapping her in an undersea cave

While diving in the sea near the West Indies, Dr. Darian and Brock are startled when they are attacked by a bizarre mutant life form...a creature composed entirely of seaweed, which continues to grow increasingly larger as the plant beast merges with more and more seaweed. The two divers barely escape the plant creature's two huge tendrils as they frantically swim back to the Calico. There they call upon Godzilla to deal with the creature, and while the Seaweed Monster is no match for Godzilla, the Kaiju King can't seem to severely injure the plant creature's physical substance. As the Seaweed Monster menaces a nearby inhabited island, Dr. Darian notices that a severed piece of the creature completely dried up after excessive exposure to sunlight. Thus, she directs Godzilla to drag the Seaweed Monster onto land, where the searing tropical sunlight eventually causes the plant creature to wither and die.

As a result of the pollution caused by a nearby oil spill in Chesapeake Bay, a huge gelatinous monster is spawned (perhaps inspired by Hedorah) that survives by feeding upon various metals. The ameoba-like kaiju, referred to as the Breeder Beast, begins heading towards the U.S. Mint for its stores of gold, silver, and platinum. Godzilla is called by the Calico crew to stop the beast, but the creature's jelly-like substance appears invulnerable to Godzilla's physical attacks. Dr. Darian believes that the Breeder Beast's glowing nucleus may potentially turn it into a living nuclear bomb due to all of the gases and metals the creature has fed upon, so she urges Godzilla and the National Guard not to attack it. However, when Godzilla disobeys and blasts the monster with his laser beams, the beast doesn't explode, and Dr. Darian now believes that the creature has learned to control its rampant energies. Thus, she directs Godzilla to project his laser beams into the Breeder Beast's nucleu

The team becomes stranded in the Himalayas and are imprisoned by a race of Abominable Snowmen. Godzilla must find and rescue them before it is too late.

When the Calico is about to be struck by a falling satellite, Godzilla is called to the rescue. Although the Big G saves the crew by catching the satellite, energy emissions from the device create a freak time warp that sends Godzilla and the Calico back one million years in the past. There they are soon attacked by a Diplodocus, who the much larger Godzilla easily drives away with a few spurts of his fiery breath [actually, the Diplodocus, a prehistoric herbivore which resembled the Apatatosaurus in body form but was lighter and much longer in length with a somewhat elongated head, was a peaceful creature and shouldn't have attacked the crew; for that matter, dinosaurs of that type became extinct before the end of the Jurassic Period, over 100 million years ago, and shouldn't have co-existed with either the Tyrannosaurus or the cavemen seen later in this episode]. While exploring the prehistoric terrain, the crew meet and befriend a tribe of cavemen who they teach to defend themsel