As the city that produces the most selium - that precious gas that elevates airships and powers strange magic - Hond Steading is a jewel worth stealing. To shore up the city’s defenses, Detan promises his aunt that he’ll recover Nouli, the infamous engineer who built the century gates that protect the imperial capital of Valathea. But Nouli is imprisoned on the Remnant Isles, an impervious isla...