Six months have passed since United Earth Defense Fleet (UEDF) cadets Ryan Thompson, Amanda Williamson, and their senior class saved earth from destruction at the hands of the Altarrans. It seems like yesterday that they learned startling truths about the strange invaders from Altarra, and undertook the adventure of a lifetime. As the cadets now prepare for graduation, Amanda is haunted by vivid nightmares of another alien race, this one much more deadly, and with a mission to annihilate all life within our galaxy. Worse, she's having mysterious blackouts and apparent visits from an ancient entity, who warns that the Karang are coming. With the help of their former enemies, the Altarrans, Ryan, Amanda and the entire UEDF must hold off the Karang against all odds, while searching for a long-hidden, legendary weapon known as the Ship of the Gods, which may be the only slim hope for Earth's survival.