Nick is worried that one of Godzilla's egg might have survived the events of the 1998 Godzilla movie. When Godzilla's offspring hatches indeed from a single surviving egg, Nick and his science team known as "H.E.A.T." must stop it.
It turns out that Godzilla's offspring, also named Godzilla, thinks Nick is its parent, since he was there when it hatched. Nick and his team use this to get Godzilla to help them fight a new giant mutant threat - angry deep-sea squids.
Costo Rojo, a fictional country in Central America, is plagued by a giant mutated worm, El Gusano Gigante. H.E.A.T. and Godzilla help, but the countries strongman, General Albondiga, attacks it with bio-weapons and makes things worse.
Nick's nemesis from college, who now owns a tech business empire, offers him and the team a partnership. Is this a friendly ploy of a changed man or a devious attempt to get Godzilla.
H.E.A.T. and Godzilla must find a way to stop bio-engineered microbes, designed to clean up New York by eating all the garbage, when they start eating everything in their path.
H.E.A.T. and Godzilla must stop the infestation of giant mutant rats in New York's sewers. Meanwhile, some trophy hunters plan to take on the ultimate prey - Godzilla.
H.E.A.T. must resolve the mystery behind the strangest mutant they've ever seen - the so-called Crackler that uses electricity in its attacks. Is it a product of a freak mutation, science or just one man's dream?
A seemingly dormant giant alien spacecraft that's been at the bottom of the Pacific Ocean for 65 million years is discovered and dubbed Leviathan. H.E.A.T. is sent to find the scientist who went missing while exploring it.
A mutant creature that resembles Quetzalcoatl, a Mesoamerican deity that looks like a feathered serpent, is attacking villages in Mexico. Elsie, a member of H.E.A.T., has personal interest in this case.
H.E.A.T. must battle on two fronts. On one hand, a dangerous giant mutant bat has appeared in Nigeria. On the other, the U.S. military now has the alien ship Leviathan, but its alien owners arrive with their army of monsters.
Japanese military believes that Godzilla is a threat to the world and plans to kill it. Tables turn when giant mutant King Cobra lets itself loose on Tokyo.
Pentagon sends H.E.A.T. to the Canary Islands, where a US military base is located, to stop a giant mutated black widow that's breading at incredible speed and is slowly taking over the place.
Godzilla seemingly attacks New York, so French secret agent Phillipe Roache (seen in the 1998 movie Godzilla) is sent again to kill Godzilla. However, H.E.A.T. believes that something or someone has set Godzilla up.
Alien device called Techno-Sentient arrives on Earth and melds with human technology, including the Internet, with only one goal - to locate the Earth's nuclear silos and activate the weapons held inside.
H.E.A.T. must stop Mimic, a creature that can mask itself as anyone it touches. It was created in a secret genetic experiment conducted by the French in the Amazon jungle and has only one goal in mind - to reproduce and take over.
