WHEN A STRANGER CALLS

Jill Johnson (Carol Kane) is babysitting the children of Dr. Mandrakis (Carmen Argenziano) at his home. When the children are asleep, Jill receives a telephone call from a man who asks her if she has checked the children. Jill initially dismisses the call as a practical joke. However, he calls again and again, the calls increasing in frequency and threat level, and Jill becomes frightened. She calls the police, who tell her to keep the perpetrator on the line long enough for them to trace the call. Jill receives one final call from her harasser. Immediately after the conversation, the police phone to inform her that the calls are coming from a line located somewhere inside the house. Jill sees the intruder's shadow. Unbeknownst to her, an English merchant seaman named Curt Duncan (Tony Beckley) killed the children shortly after Jill arrived. He leaves Jill unharmed and, after his trial, is sent to a psychiatric facility.

Seven years later, Duncan escapes from the psychiatric facility. Dr. Mandrakis hires John Clifford (Charles Durning), who investigated the earlier murders but is now a private detective, to find Duncan. Not knowing Clifford is after him, the homeless Duncan is beaten after harassing a woman, Tracy (Colleen Dewhurst), in a downtown bar. Duncan follows Tracy to her apartment and she takes pity on him. She tries to be nice to him while getting him to leave, hoping this will be the last she sees of him.

Meanwhile, an increasingly obsessed Clifford confides to his friend Lieutenant Garber (Ron O'Neal) his intention to kill Duncan rather than have him recommitted. Garber, who was also present at the Mandrakis crime scene, agrees to collaborate. Clifford tracks Duncan to Tracy's residence. He tells Tracy that Duncan literally tore the Mandrakis children apart with his bare hands and Tracy reluctantly agrees to act as bait at the bar that evening in an effort to draw Duncan out. Duncan never appears. After Clifford leaves, however, Duncan comes out of hiding from inside Tracy’s closet. Tracy screams for help and Clifford returns, chasing Duncan from the scene but losing his trail in the streets of downtown Los Angeles.

Jill is now married with two young children. One night, she and her husband Stephen (Steven Anderson) go to dinner to celebrate his promotion while their children are babysat by Sharon (Lenora May). While at the restaurant, Jill gets a telephone call and hears Duncan's voice asking again: "Have you checked the children?" The police escort Jill back home to discover that everything there is fine.

Upon hearing about the incident, Garber alerts Clifford. Clifford tries to call Jill, but finds that the line is dead in an eerie parallel to Jill's original stalking. Later that night, Jill hears Duncan's voice as the closet door appears to open. She tries to awaken her husband only to realize that the man lying next to her is the intruder. He chases Jill across the room and attempts to kill her, but Clifford arrives in time to shoot Duncan in the chest, killing him. Jill's husband Stephen is in the closet, unconscious but alive. Their children are safe.