The film began with Cara returning home after collecting several Missing Dog posters, giving them to Amy in return for a "surprise": the dog from the posters, which Amy had presumably killed and taxidermied to serve as their family's pet. As Cara held the dog, the doorbell suddenly rang, with Amy giving her sister a nod upon seeing that there was a woman at the front door. Amy opened the door and the woman (a saleswoman named Katherine) introduced herself and asked if Amy's mother was home, with Amy saying she "was now" and invited Katherine to "make herself at home".
As Katherine entered the home, Amy came up behind her with a baseball bat and struck her several times in the head, killing her before she and Cara marvelled at how "great" it was that their "mother" came to them directly. Afterwards, the murderous sisters looked outside the front windows together, agreeing that what they needed now to complete their twisted family was a brother. Cara then called out to her father to ask when school began, only for Amy to scold her, as William's favorite show was on. Amy then brought her sister to their father's room to apologize for interrupting, serving as the reveal that William was also dead and been taxidermied by his deranged daughters. Cara and Amy gave a sinister glare to the camera as the film ended, with the credits playing over a scene of the girls playing with their new "pet".