Aria is a world riddled with an epidemic. Two years have passed since the day strange monsters emerged from out of nowhere, paralyzing the otherwise peaceful lives of its citizens. Since then, few people dare to live outside the confines of the cities, fearing the dangers lurking beyond the protection of a mysterious army known as "the Knowms." Lucas Bardsson is one of the rare exceptions, valuing the privacy of rural living despite its inherent perils. Some might consider him reckless or perhaps even brave. For Lucas, however, this way of life has become little more than ordinary. But it all changes the day he stumbles across a peculiar object of unimaginable importance. Upon learning of its significance, he unwillingly becomes entangled in a series of events that alter his life, his character, and his world.