You've got the easiest summer job ever—baby-sitting little Katie Harper. You've never baby-sat before, but the Harpers are paying you $7.50 an hour—an offer you can't refuse. Baby-sitting a two-year-old will be a snap. Or so you thought. There's something creepy about Katie. When her parents are around, she's a perfect angel. But when they leave, Katie turns into something frightening. Something you don't want to mess with. Is it all in your head? Or is Katie evil?