Two young siblings, Becca and Tyler, embark on a week-long visit to their grandparents' remote Pennsylvania farm, whom they've never met due to a long-standing family estrangement. Their mother sends them off with the hope of rekindling familial bonds. Becca, aspiring to be a filmmaker, decides to document their experience, hoping to capture the family reunion and perhaps understand the nuances of the estrangement. Tyler, her supportive younger brother, has his reservations but goes along with the plan. Upon arrival, they are warmly received by their grandparents, who seem eager yet slightly awkward about hosting them.

As the days progress, Becca and Tyler begin to notice increasingly strange and disturbing behavior from their grandparents, particularly after 9:30 PM, which they are adamantly told to avoid leaving their room. The rules of the house, initially attributed to old age quirks, soon escalate into terrifying nightly activities that the siblings can't ignore. Driven by curiosity and concern, they decide to secretly investigate, leading them to uncover unsettling truths. Their initial excitement for familial bonding transforms into a desperate quest for understanding and survival, as they confront what lies beneath the surface of an apparently idyllic reunion.