Things appear normal until two children discover that Grandma and Grandpa (Deanna Dunagan and Peter McRobbie) are involved in something deeply disturbing after being left to stay at their grandparents' house while their mother is on vacation. They are warned not to come out of their room past 9:30 at night, but when they do they realize that there is something terribly wrong with their grandparents. After pleading online to their mom for rescue, they realize that they are on their own against the seemingly evil elders.