The early 21st Century witnessed the onslaught of an all-out monster war. The special aircraft sent to stop the creatures appeared to have little effect on their foes, that is, until help arrived. Suddenly, one-by-one, the monsters of the world began disappearing in the presence of enormous, unidentified flying objects. The three ships, the α, ß, and γ, converged on Tokyo, where they connected to their Mothership: a massive, spherical battle station of ultimate destructive powers. However, the race of aliens that inhabited the ships, known as the Xiliens, seemed to come in peace. They appeared as though they wished to save the Earth from total destruction. As time passed, the truth was uncovered. These "friendly" aliens were not at all friendly; in fact, they wanted to enslave the human race! When their plans were ultimately revealed, the monsters' transport ships released the creatures on the world once more. The Xiliens looked on from their exotic vessels, confident that the planet that they looked down upon was their new home planet...

The aerial battle cruiser, Gotengo, put a wrench in the Xiliens' plans for destruction. The craft journeyed to the bottom of the world, and unleashed an Earth monster of tremendous power: Godzilla. When he easily “killed” one of the Xilien's most powerful monsters, Gigan, the aliens realized the situation had become far more complicated than originally perceived. The Xilien transport ships were sent to collect the monsters, for their leader realized he could send his own monsters to fight off this new menace. Zilla, a towering, bipedal lizard, was sent to Sydney aboard one of the giant transport vessels, but the creature suffered a miserable defeat as it was killed atop the famous Sydney Opera House. When Godzilla passed through New Guinea, one of the transport ships released Kumonga, and this monster presented the first real challenge. Though it appeared to pull an advantage over Godzilla, it was ultimately flung many kilometers into the distance. When Godzilla reached Japan, another ship released Kamacuras, but that horrific arthropod was killed atop an electrical conductor. Once Godzilla reached Mt. Fuji, all three of these transport ships, the α, ß, and γ, unleashed Anguirus, Rodan, and King Caesar in order to defeat Godzilla in one fell swoop. Piled on top of one another, this latest victory marked one more defeat for the Xiliens. The craft returned to Tokyo and the Xilien Mothership.

During the ensuing climactic battle, the three ships were destroyed in a raging inferno when the Mothership initiated its self-destruct mechanism. With the Xilien invasion force completely annihilated, the world was saved from total destruction.