A new and deadly mutation, a plant-like creature known as Bacillus (who may have been inspired by Biollante), appears and begins wreaking havoc, prompting H.E.A.T. to call upon Godzilla. During the battle, Godzilla is seriously injured and rendered catatonic as the result of being injected with a highly dangerous form of mutated bacteria by Bacillus. In order to save their kaiju ally, Tatopoulos and Monique travel within Godzilla's body in order to carefully exterminate all of the mutant bacterium. Now fully healed, Godzilla attacks Bacillus anew, and eradicates the creature with his incendiary breath.

Una nueva y letal mutación, una criatura con aspecto de planta conocida como Bacillus (que puede haberse inspirado en Biollante), aparece y comienza a causar estragos, lo que hace que H.E.A.T. llame a Godzilla. Durante la batalla, Godzilla queda gravemente herido y catatónico al ser inyectado por Bacillus con una forma muy peligrosa de bacteria mutada. Para salvar a su aliado kaiju, Tatopoulos y Monique viajan dentro del cuerpo de Godzilla para exterminar cuidadosamente toda la bacteria mutante. Ahora, completamente curado, Godzilla ataca de nuevo a Bacillus y erradica a la criatura con su aliento incendiario.