When the Earth's polar ice caps begin melting at a terrifying pace, the United Nations sends an expeditionary force to investigate... one that is completely destroyed by the vanguard of an invasion from beneath the Earth! As the whole planet watches in horror, the U.N.'s naval armada is crushed beneath the invaders' giant gravitonic rings! The nations of the world are helpless, but even as the enemy's giant cylinders encircle the globe, a secret organization of men and women being to mobilize a last ditch defense, a secret weapon built for, but never used in, World War II. After fifty years in hiding, the ultimate attack sub is finally going to get its baptism by fire... with the fate of all mankind hanging in the balance!

Prepare yourself for the ultimate showdown as the Avatar's subterranean armada strikes hard in their brutal bid to destroy every human on the surface of the Earth! Between Avatar's giant gravitonic rings, each of which carries the crushing force of a captive black hole, and her monstrous microwave emitting battle cylinders, the combined forces of the world's nations don't stand a chance... but Avatar is mistaken in her belief that her forces are unbeatable. Standing against them is a single amazing ship, the Ra, a Yamato-class battle sub secretly rebuilt after its supposed destruction in World War II by a handful of dedicated warriors who now claim allegiance to no country. Joining them are the mysterious Annette, descendant of a lost civilization, and Go Arisaka, the sole survivor of a vanquished UN Peacekeeping Force who must find a way to work with his estranged father, once missing and presumed dead and now the captain of the Ra.