Kaina, Ririha, and Yaona descend into the bowels of the royal palace to prove the existence of the Great Orbital Spire Tree, but just as they find the evidence they're looking for, Valghia unleashes a monstrous weapon…Can Kaina and his friends save Atland from destruction?! The climactic final chapter in the tale of the young heroes striving to change the fate of their dying world!