In the darkness of a vast cave system, cut off from the world for millennia, blind creatures hunt by sound. Then there is light, there are voices, and they feed. Swarming from their prison, they multiply and thrive. To scream, even to whisper, is to summon death.

Deaf for many years, Ally knows how to live in silence. Now, it is her family's only chance of survival. They must leave their home, shun others, and find a remote haven where they can sit out the plague. But will it ever end? And what kind of world will be left?