The Visit (2015 American film) (2015)

Two siblings from Philadelphia, Becca and Tyler, prepare for a five-day visit with their grandparents while their divorced mother Loretta goes on a cruise with her boyfriend. Loretta has not spoken to her parents in fifteen years after they disapproved of her marrying her high school teacher, and she simply sends her children, sight unseen, to her parents. Having never met their grandparents, the teens plan to record a documentary about their visit using a camcorder.

Becca and Tyler meet their grandparents, referred to as "Nana" and "Pop Pop", at a train station. Arriving at Nana and Pop Pop's isolated farmhouse, Becca and Tyler are instructed to never go into the basement and to not leave their room past 9:30 p.m. Although at first the grandparents seem pleasant, their behavior gradually becomes peculiar – Becca catches Nana projectile vomiting, Nana chases the teens during a game of hide-and-seek, Tyler finds a pile of soiled diapers in the shed, and Pop Pop attacks a man in town that he thinks is following them. When challenged, both grandparents are dismissive of each other's behavior: Pop Pop claims that Nana is sundowning, while Nana claims that Pop Pop is incontinent. As the erratic behavior intensifies, Becca and Tyler's documentary-style film evolves into one of mystery-solving and evidence collection.

Stacy, a woman Nana and Pop Pop helped in counseling, brings a blueberry cobbler to thank them, but is not seen leaving. Tyler decides to secretly film the living room during the night, but Nana discovers the camera and tries unsuccessfully to break into the children's locked bedroom with a knife.

Becca and Tyler call Loretta, begging her to come and collect them. Loretta asks where their grandparents are, and Tyler points the laptop's webcam out the window to show her they are in the backyard. Loretta panics and tells Becca and Tyler that the people they are staying with are not their grandparents. The teenagers attempt to escape and discover Stacy's body hanging from a tree. The "grandparents" find the children and force them to play Yahtzee. Later, Becca sneaks into the basement and finds the decomposed corpses of their real grandparents, along with uniforms from the psychiatric hospital at which they worked, revealing that Nana and Pop Pop are actually escaped patients who murdered the grandparents and stole their identities. Pop Pop grabs Becca and imprisons her in his bedroom with Nana, who tries to attack her in a psychotic fit. He then torments the germophobic Tyler by smearing his face with his soiled diaper. Following a struggle, Becca fatally stabs Nana with a glass shard from a broken mirror, then runs to the kitchen and attacks Pop Pop. As Pop Pop gains the upper hand, Tyler knocks him to the floor and kills him by repeatedly bashing his head with the refrigerator door. The teens escape outside, where they are met by their mother and police officers.

In the aftermath, Becca asks Loretta about what happened between her and her parents. Loretta reflects that she had a major argument with them, during which she hit her mother and was then struck by her father. Loretta then left home and ignored their attempts to contact her. Loretta concludes that reconciliation was always possible had she wanted it. She advises her children not to resent their father for abandoning them, and Becca decides to include footage of her father in their documentary after stating earlier that she would not do so.

During the credits, Tyler records and does a freestyle rap back at home about his and Becca's misadventure with the fake grandparents, while Becca looks on approvingly.