When Grace’s husband, Adam, inherits an isolated North Yorkshire cottage, they leave the bustle of London behind to try a new life. A week later, Adam vanishes without a trace, leaving their baby daughter, Millie, in her stroller on the doorstep. The following year, Grace returns to the tiny village on the untamed heath. Everyone --- the police, her parents, even her best friend and younger sister --- is convinced that Adam left her. But Grace, unable to let go of her memories of their love and life together, cannot accept this explanation. She is desperate for answers, but the slumbering, deeply superstitious hamlet is unwilling to give up its secrets.
As Grace hunts through forgotten corners of the cottage searching for clues, and digs deeper into the lives of the locals, strange dreams begin to haunt her. Are the villagers hiding something, or is she becoming increasingly paranoid? Only as snowfall threatens to cut her and Millie off from the rest of the world does Grace make a terrible discovery. She has been looking in the wrong place for answers all along, and she and her daughter will be in terrible danger if she cannot get them away in time.