A decade ago, the Erebonian Empire launched a devastating attack on the Kingdom of Liberl, marching all the way to the capital before being repelled by Cassius Bright's determined counteroffensive. Presently, with the invaders poised on the northern borders, eyeing Liberl's advanced technology and magic, the Bracers Guild is assisting the small kingdom in its gradual recovery, deploying their expertise in "Craft" to shore up its defense. Estelle Bright, daughter of Cassius, and her adopted sibling Joshua regard these events as mere history lessons. Yet, history often tends to repeat itself and, as they ready themselves to join the Bracers Guild, malicious elements conspire to throw them into a familiar situation, placing them at the wrong place and time. When their father's airship suddenly disappears, it falls onto the inexperienced but competent teenagers to undertake an audacious rescue mission of their own!