Barbara is an ordinary twenty-year-old student who is hired to look after the two children of the wealthy Adams family while their father and mother go on vacation for a week. She has a large secluded house, a car, and Cindy and Bobby, whom she watches, are obedient and kind. But only at first glance. One morning Barbara wakes up tied to her bed. At first she thinks that the children are joking or, as they explain, they want to feel free from adult supervision. But the joke drags on and soon develops into a real nightmare. After all, Bobby and Cindy have friends, and they have completely different plans.