Fifteen-year-old Becca and her slightly younger brother Tyler are sent for a week-long stay in rural Pennsylvania to stay at the home of the grandparents they've never met while their single mother decides to treat herself to a romantic cruise with her new beau. Their first time staying with the elderly for an extended period, the kids are disturbed by the behavior of their Nana and Pop Pop, including Nana's cavorting around the house nude in a manic state, or Pop Pop's tantrums and mysterious trips to he secluded shed outside.