Alliance Insurgent: The Alliance Trilogy, Book 3

An apparent naval victory turns to chaos when the Adjudicators awaken an ancient star leviathan and send it against the allied fleet. Falling back to friendly territory ahead of this terrifying weapon, Jess Tolvern and the allied command muster the combined forces of the Alliance planets to finally defeat the Adjudicators and push across the inner frontier to reestablish contact with the remaining civilizations of Old Earth.