Iris Blum, a retired horror writer, suffers from dementia and lives in a remote house in Braintree, Massachusetts. The house was built by a man for his new bride, but the couple vanished on their wedding day and left the house unfurnished. Iris's estate manager, Mr. Waxcap, hires live-in nurse Lily Saylor to care for her. On Lily's first night in the house, the telephone is wrenched out of her hands by an unseen force. After picking it up and walking away from the arch, a figure in white walking backwards is seen. A spot of black mold appears on a section of wall and slowly grows as the months pass. Lily often finds a corner of the rug at the base of the stairs has been flipped up, but she is the only person in the house who walks on the first floor.