Something terrifying. Something you can't see. One look leads to an attack of deadly violence. Nobody knows what it is. Nobody knows where it came from.

Five years after this thing appeared, only a handful of survivors remained. One of them is Malorie and her two young children. Living in an abandoned riverside house, Malorie had long dreamed of fleeing to a place where her family might be safe. But the journey would be terrifying: over thirty kilometers, by boat, downriver blindfolded, relying solely on Malorie's intelligence and her children's trained hearing. One wrong move and they will die. Something is following them. But it is not known if it is a human, an animal or a monster?