Welcome to the age of airships. It is a world powered by steam and innovation, ruled by an elusive empress at its heart. Seventeen year-old Jorun is not part of this world. Hers is one of hidden tunnel networks and lights that dance across night skies, on that has remained separate from the rest of society for over a thousand years. This all changes when a boy appears from nowhere, raving about invaders from a faraway land. Purely by chance, Jorun soon finds herself in the middle of a struggle unlike anything she could have ever dreamed of, and must come to the realization that only she can stop an impending war.