After their escape from the Ark and a 7 month Nap, Chief and Cortana find themselves in the Sol System, but not the one they know, Earth is all but Destroyed by a Tyrannical Race known as the Gamilans, they must help the crew of the Space Battleship Yamato make her Maiden Voyage to Iscandar and back within a year to save Humanity from Extinction

Just before the Battle of Trost, something falls from the sky, and no one had expected the turn of events that came after, or who had accompanied it.