In this Simon West remake of the memorably creepy 1979 original, teenage babysitter Jill Johnston (Camilla Belle) is responsible for the safety of two sleeping children in a large, empty house. She starts receiving frightening prank calls. At first dismissive of them, she becomes convinced that they're a genuine threat and calls the police to have the calls traced. When the trace reveals that the calls are coming from inside the house, terror ensues. Has she checked the children?