Jill Johnson (Carol Kane) is babysitting the children of Dr. Mandrakis (Carmen Argenziano) at their home. When the children are asleep, Jill receives a telephone call from a man who asks her if she has checked the children. At first, Jill dismisses the telephone calls as a practical joke. However, as the calls become more frequent and threatening, Jill becomes frightened and decides to call the police, who promise to trace the caller if Jill keeps him on the telephone line long enough. Jill, frightened to extreme measures, arms herself as she receives one final call from the nefarious stalker. Soon after the conversation, Jill receives a call from the police, only to find out that the stalker is calling from inside the house. A light comes on at the top of the staircase, and Jill sees the stalker's shadow. In a panic, she immediately runs to the door, unhooks the chain lock only to reveal a close-up of a detective when she screams. The camera then zooms out.