As both the Godzilla Squad and Robert, in the Red Ronin, speed after Godzilla, Godzilla is suddenly transported to the moon. There, he fights the Beta-Beast, which Godzilla eventually destroys with his fire breath.
Following the Beta-Beast's defeat, Godzilla is confronted by the aliens who transported him to the moon: the Betans. These aliens appeal to Godzilla, telling the monster that their world has been at war against the Megans for centuries using giant monsters as weapons against each other. With the war effort depleting the Megan supplies, they have sent three of their monsters, Triax, Rhiahn and Krollar, to Earth in order to plunder it.
Godzilla accepts the mission, and he is transported back to Earth just as the Red Ronin is confronted by the first of the invaders: Triax.