Rod Serling said that this story was based on a real-life experience that he had.

In the original story " The Mirror Image", the washroom attendant was actually a woman working at the lunch counter.

Vera Miles later portrayed Janet Leigh's sister in Alfred Hitchcock's legendary Psycho.

Martin Milner is best known as Officer Pete Malloy from the TV series Adam 12.

Opening Narration
Narrator: Millicent Barnes, age twenty-five, young woman waiting for a bus on a rainy November night. Not a very imaginative type is Miss Barnes, not given to undue anxiety or fears, or for that matter even the most temporal flights of fancy. Like most young career women, she has a generic classification as a, quote, girl with a head on her shoulders, end of quote. All of which is mentioned now because in just a moment the head on Miss Barnes' shoulders will be put to a test. Circumstances will assault her sense of reality and a chain of nightmares will put her sanity on a block. Millicent Barnes, who in one minute will wonder is she's going mad.

Millicent Barnes: Excuse me.
Bathroom Attendant: Hmm?
Millicent Barnes: The bus to Courtland...
Bathroom Attendant: What about it?
Millicent Barnes: Well, it was due a half an hour ago.
Bathroom Attendant: Yep, half hour ago.
Millicent Barnes: When will it be in?
Bathroom Attendant: Hard to say. It's been raining hard, roads slick, maybe a bridge or two out.
Millicent Barnes: Well, when do you think it will be in?
Bathroom Attendant: She'll be in when she'll be in, that's all! I told you that the last time you asked, miss!
Millicent Barnes: The last time I asked? The last time I asked was right now. Look, all I want from you is a civil answer!
Bathroom Attendant: You're gettin' a civil answer!! Trouble is, every ten minutes you're up here acquirin' one! Situations just don't change that rapidly. You wanna know about the Courtland bus? It's late. It was late when you asked a half hour ago, late when you come back fifteen minutes later, and it's late now. And all the asking in the world ain' gonna push it none!
Millicent Barnes: But this is the first time I've been up here, the very first time! Either you need your eyes...
Bathroom Attendant: Now whats a matter?!
Millicent Barnes: Nothing, nothings the matter.

Millicent Barnes: I've been thinking about something. It's very odd...but I've been remembering it.
Paul Grinstead: Remembering what?
Millicent Barnes: About something I read or heard about a long time ago about different planes of existence, about two parallel worlds that exist side-by-side and each of us has a counterpart in this world, and sometimes through some freak, through something unexplainable, this counterpart, after the two worlds converge, comes into our world and in order to survive it has to take over.
Paul Grinstead: Take over?
Millicent Barnes: Replace us. Move us out so that it can live.
Paul Grinstead: That's a little metaphysical for me.
Millicent Barnes: I remember reading it somewhere. Each of us has a twin in this other world, an identical twin. Maybe that woman I saw...
Paul Grinstead: Millicent, there's another explanation. There has to be. One that comes with more reason.
Millicent Barnes: I can't explain it, but I know that's what's happened. This other woman, my counterpart...
Paul Grinstead: Forget about it, please! Don't think about it. I just thought of something. I've got a good friend, lives in Tully. I'll call him. Maybe he'll bring his car down here for us. He might even be able to drive us into Syracuse. I'll call him. Alright, Millicent? Shall I call my friend?

Bathroom Attendant: I'll tell you what I think. I'd say she's got a leak in her attic. Parallel planes! Counterparts from another life! You got a thing about sick people, is that it?

Closing Narration
Narrator: Obscure metaphysical explanation to cover a phenomenon, reasons dredged out of the shadows to explain away that which cannot be explained. Call it parallel planes or just insanity. Whatever it is, you find it in the Twilight Zone.