For as long as Fei can remember, there has been no sound in her village, where rocky terrain and frequent avalanches prevent residents from self-sustaining. Fei and her people are at the mercy of a zipline that carries food up the treacherous cliffs from Beiguo, a mysterious faraway kingdom. When villagers begin to lose their sight, deliveries from the zipline shrink and many go hungry. Fei s home, the people she loves, and her entire existence is plunged into crisis, under threat of darkness and starvation. But soon Fei is awoken in the night by a searing noise, and sound becomes her weapon.