The Erebonian Empire is on the brink of all out war! Taking place shortly after the ending of Trails of Cold Steel III, the heroes of Class VII find themselves against the full force of the Empire in an attempt to stop its path of total domination. Further, the hero of the Erebonian Civil War and Class VII's instructor, Rean Schwarzer, has gone missing. Now, the students of Class VII, old and new, must unite with heroes from all over the continent to create the only chance the world has to be spared from total destruction.