A man abducts three young children and tortures them in a subterranean lair.

The S. S. Claridon is scheduled for her five last voyages after thirty-eight years of service. After an explosion in the boiler room, Captain Robert Adams is reluctant to evacuate the steamship. While the crew fights to hold a bulkhead between the flooded boiler room and the engine room and avoid the sinking of the vessel, the passenger Cliff Henderson struggles against time trying to save his beloved wife Laurie Henderson, who is trapped under a steel beam in her cabin, with the support of the crew member Hank Lawson.

The 9th Godzilla film was the last made by the original Godzilla creators, and was meant to be a grand finale. Aliens have released all the giant monsters from their imprisonment on Monster Island and are using them to destroy earth’s major cities. It is up to the daring crew of the super rocket ship X-2 to infiltrate the aliens’ headquarters before the Earth monsters and King Ghidrah annihilate the planet.