 A young high school student, Jill Johnson (Kane) is babysitting one night for a physician and his wife. During the evening, a mysterious phone caller begins taunting her. Sometimes he simply says nothing, other times he asks,  Have you checked the children? . Jill eventually becomes frightened for her safety and calls the police. The police successfully trace his next call and discover something horrifying - the calls are being made from INSIDE THE HOUSE! Police are immediately dispatched and Jill narrowly escapes into the arms of Lt. Clifford (Durning). Officers soon discover that the children had been savagely murdered hours ago by the caller, who had been using a phone the parents never had disconnected. 7 years later, the murderer (Tony Beckley) escapes from a mental hospital and resumes his demented mission - this time going after Jill s husband, Steven - and their children. And Clifford - now a P.I. hired by the father of the murdered children - is also hunting the murderer...