Matt is a pharmaceutical salesman who met his wife Shelby, a yoga instructor, when he won a yoga class at a work raffle. They appear on a documentary-style show called "My Roanoke Nightmare." After a gang initiation attack that lands Matt in the hospital and causes his wife Shelby to have a miscarriage, the couple away from the city and buy an old, isolated fixer-upper house in North Carolina, where Matt grew up and where his mother and sister still live. They outbid a group of sketchy country bumpkin-types. They are surprised at how inexpensive the property is and are told by the auctioneer that they cannot build on the surrounding property because it is protected.
A series of strange events start plaguing the couple. One night, the two are interrupted in the middle of sex, the two are interrupted by pig-like noises and a loud banging. Matt goes to investigate and finds a big mess of torn apart garbage outside, briefly thinking it might be the hillbillies they encountered earlier. Shelby hears what she thinks is hail, but sees it's actually a torrent of teeth pelting the house. When she goes to show Matt when he returns home, the teeth are gone and he insinuates that she was imagining things.
While Matt is away on sales business, Shelby sees two random, strange women walking through the house. She is later attacked and nearly drowned while lounging in their outdoor hot tub. This police are called and Matt rushes home, with the police suggesting that Shelby made up the attack (which she said was done by people in old-timey costumes carrying torches and pitchforks) given that there is no physical evidence. Matt mentions the hillbillies trying to scare them off and the policeman believes it might be the Polks.
Later, a pig is left at their doorstep, which Matt buries without telling Shelby. Matt also installs security cameras all over the property before leaving on business.
Matt's sister Lee is a police officer who was injured on the job when she was shot during a house raid and became addicted to painkillers. Her addiction was discovered after a serial rapist she was pursuing kills himself in front of her. Her husband divorced her after she was fired by the police force, and he gained majority custody of their daughter.
Lee stays with Shelby while Matt is away. There is increasing tension between the two women -- neither like the other's place in Matt's life. Lee is distrustful of what Shelby claims to have been seeing, while Shelby believes that Lee is trying to spook her.
Late at night, Lee is awoken by strange pig-like noises and someone rolls an empty bottle of wine into her room. Lee accuses Shelby and they argue. Meanwhile, hours away on business, Matt gets an alert and sees on the security camera a torch-carrying mob approaching the house. When he calls to warn them, no one answers the phone.
Lee and Shelby stop arguing once Lee hears someone in the house. They follow grunting male sounds in the basement and find a home video playing. In the video, a man says "I knew it was real" and is attacked by a pig-man creature. Lee and Shelby become trapped in the basement, hearing many footsteps upstairs, after all the lights go out, while Matt races to get home in time.
Lee and Shelby go upstairs, not finding anyone there but finding stick figures hanging all over the house. The cops write it off and when Matt returns home, he also believes that the hillbillies are just trying to run them off. Shelby is upset that no one is taking it seriously and drives off on her own.
Matt frantically calls her. Shelby picks up while driving and, because she is distracted, hits a woman in old-fashioned clothing who is in the middle of the road. Startled, Shelby gets out of the car and attempts to help the woman, who ignores her and walks into the woods. Frightened and alarmed, Shelby follows her, but loses the woman and becomes lost herself in the woods.
She stumbles upon more of the stick figures hung from many trees and falls to the ground, where she sees the earth and landscape actually shift and move. Running scared, she then stumbles upon a group carrying pitchforks and wearing old-fashioned clothing, screaming in fright when she sees one of them ambling towards her with a head wound.