Jinto and Lafiel are riding on the lightly-armed transport ship Bokbrusue and navigating at the planar space of the Hyde System. Jinto was officially appointed to govern the Hyde System as Earl, which returned to imperial rule after the Union retreated. However, the government of Martine, Jinto's motherland, is resisting obstinately against the Empire. Meanwhile, the First Devastation Fleet, formed with a new ship type called Attack Vessel, is traveling to the Hyde System for drilling practices.