Five years ago, sisters Victoria and Lilly vanished from their suburban neighborhood without a trace. Since then, their Uncle Lucas and his girlfriend, Annabel, have been madly searching for them. But when, incredibly, the kids are found alive in a decrepit cabin, the couple wonders if the girls are the only guests they have welcomed into their home.

As Annabel tries to introduce the children to a normal life, she grows convinced of an evil presence in their house. Are the sisters experiencing traumatic stress, or is a ghost coming to visit them? How did the broken girls survive those years all alone? As she answers these disturbing questions, the new mother will find that the whispers she hears at bedtime are coming from the lips of a deadly presence.