In the year 2199, the Earth has been under radioactive siege from extraterrestrials, known as the Gamilas, for five years. The Earth's defense forces have been decimated and any surviving humans have had to move underground to escape the radioactive bombardment. Unfortunately, the contamination is slowly penetrating the earth and beginning to affect the underground facilities. The last interstellar battleship of the exhausted Earth Defense Forces, the Yamato, sets out on a mission to Iscandar, a planet located in the Large Magellanic Cloud. There the humans hope to acquire a device that can heal the radiation damaged Earth, before the contamination wipes out the last of humanity.