Milli has a troubled past, so what she seeks today is a peaceful haven away from the hustle and bustle and potential troubles. She eagerly takes a job as a housekeeper in the grand home of the wealthy Winchester couple. She cleans, cooks, picks up her employers' daughter from school, and spends her free time alone in a small attic room. Although the behavior of the household begins to make her increasingly uneasy, she tries to ignore it. Despite everything, she envies Mrs. Winchester's luxurious, perfect life. However, when she one day discovers the Winchesters' secret hidden behind the estate's thick walls, she realizes she's facing a mortal threat. Unexpectedly, the experiences of her troubled past may come to her aid.