The story begins on Earth during a religious war between the two global powers, the UNI and the IGC. During the war, one side implements a scorched earth policy, wiping out most of humanity and leaving the Earth uninhabitable. Right before this happens, a small group of survivors leave the Earth aboard the Titan Anicetus to find a new home. They eventually find and colonize Acheron. The residents of Acheron refer to themselves as Earthborn, and descend from those who fled the Earth.