Leo and Celia, Federation knights in training, arrive at the city of Lunne to take on a special mission, led by their instructor Lisette. They are ambushed by Imperial soldiers - Leo and Celia's childhood friend Hugo and Alexandra, a young general.

Not only has the Federation's mission failed, the Empire's plans were much larger and more destructive than anticipated. Leo, Celia, and Lisette, joined by Lucien, hatch a last-ditch plan to derail the Empire's strategy.