Helen Capel is hired as a live-in lady-help to the Warren family in the countryside. She enjoys the eccentric household and her duties, but her peaceful and simple life is soon disturbed by a series of mysterious murders in the isolated community. As Helen’s employer, Professor Sebastian Warren, battens down the hatches and locks all the doors of their remote country house, the eight residents begin to feel safe. But somewhere out there lurks a murderer of young girls. As the murders crawl closer to home, Helen starts to wonder if there really is safety in numbers—and what happens when those numbers start to dwindle?