"Nightmare as a Child" is the twenty-ninth episode of The Twilight Zone.
- "Month of November, hot chocolate, and a small cameo of a child's face, imperfect only in its solemnity. And these are the improbable ingredients to a human emotion, an emotion, say, like - fear. But in a moment this woman, Helen Foley, will realize fear. She will understand what are the properties of terror. A little girl will lead her by the hand and walk with her into a nightmare."
School teacher Helen Foley finds a strange and very serious little girl named Markie (Terry Burnham) on the stairs outside of her apartment. Despite her stoic appearance, she is humming the tune of a nursery rhyme. The little girl seems to know Helen, and tries to jog her memory about a man she saw earlier that day.
The man arrives at Helen's door, and Markie runs out the back way. The man is Peter Selden (Shepperd Strudwick), who worked for Helen's mother when Helen was a child. He claimed to be the first to find her murdered mother's body. Helen witnessed the crime, but has blocked it out. When she mentions Markie, Selden tells her that was her nickname as a child and shows her an old photo of herself. She then realizes that she and Markie are one and the same.
When Selden leaves, Markie reappears. She tells Helen that she is Helen herself, and that she is there to force her to remember her mother's murder. Selden returns and confesses to killing her, and he is afraid that Helen is starting to remember and he has decided to try and kill her.
Helen manages to run into the hallway and push Selden down the stairs to his death. After talking to the police and returning to her apartment, Helen hears a young girl's voice singing the same tune as Markie. She tells the little girl she has a beautiful smile, and advises her to never lose it.
"Miss Helen Foley, who has lived in night and who will wake up morning. Miss Helen Foley, who took a dark spot from the tapestry of her life and rubbed it clean-then stepped back and got a good look at the Twilight Zone."
- Rod Serling as Narrator (voice only); uncredited
- Janice Rule as Helen Foley
- Terry Burnham as Markie
- Shepperd Strudwick as Peter Selden
- Michael Fox as Doctor
- Joseph V. Perry as Police Lieutenant [Credited as Joe Perry]
- Morgan Brittany as Little Girl; uncredited
- Rod Serling (executive producer: Cayuga Productions)
- Buck Houghton (producer)
- George T. Clemens (director of photography)
- Bill Mosher (film editor)
- George W. Davis (art director)
- Merrill Pye (art director)
- F. Keogh Gleason (set decorator; credited: Keogh Gleason)
- Henry Grace (set decorator)
- Ralph W. Nelson (production manager)
- Donald C. Klune (assistant director; credited: Don Klune)
- Franklin Milton (sound; credited: Frank Milton)
- Philip Mitchell (sound)
- Van Allen James (sound effects editor; uncredited)
- Cayuga Productions
- Columbia Broadcasting System (CBS) (in association with)
- Columbia Broadcasting System (CBS) (1960) (USA) (TV) (original airing)
- Pacific Title (titles and opticals)
- The character of Helen Foley was named after a teacher Rod Serling had in high school.
- In the "It's a Good Life" segment of Twilight Zone: The Movie, the main character is named Helen Foley and is also a schoolteacher. Helen Foley was the name of a beloved teacher of Serling's at Binghamton High School, and the main performance theater at that school is named after her.