Bob Wilson (played by William Shatner) is a salesman on an airplane with his wife for the first time since his nervous breakdown six months prior. As he stares out his window on a a stormy night, he thinks he spots a supposed gremlin on the wing of the plane. But, every time someone else looks out the window, the gremlin always leaps out of view, so nobody believes Bob's seemingly outlandish claim. Bob realizes that his wife is starting to think he needs to go back to the sanitarium, but after he sees the gremlin begin to peel back the metal on the wing he realizes that if nothing is done about the gremlin, it will cause the plane to crash. The flight attendant tries to give Bob sleeping pills, but Bob fakes swallowing them so he can stay up and do something about the gremlin. Bob then steals a sleeping policeman's revolver, and opens the window marked "Auxiliary Exit" to shoot the gremlin, succeeding despite the fact that he is nearly blown out of the plane himself. Once the plane has landed, although he is whisked away in a straitjacket, a final shot reveals evidence of his claims: the unusual damage to the plane's engine nacelle-yet to be discovered by mechanics.
Tropes at 20,000 Feet:
- Adaptation Name Change: His name was Arthur Wilson in the short story.
- Bittersweet Ending: Although Bob will go back to being in an asylum after that stunt he pulled on the plane, what counts is he stopped the gremlin from sabotaging the plane. His wife is supportive and comforting towards him, and Bob goes to the asylum with grace. What's more, it's implied that his claim might be validated once mechanics discover the damage on the wing.
- Episode on a Plane
- Griping About Gremlins
- Improbable Aiming Skills: Wilson manages to hit the gremlin with a revolver while hanging outside of a flying plane.
- Averted in the film remake, where he misses.
- Jump Scare: The scene in which Bob pulls the curtain back quickly, revealing the gremlin's face pressed against the window along with a Scare Chord.
- Large Ham: When you have William Shatner playing the main character...
- Look Ma, No Plane!
- Not-So-Imaginary Friend
- Only Sane Man: Bob's the only one to see the creature, and he can't get anyone else to believe him.
- Earn Your Happy Ending: Fortunately, Serling's ending narration implies that the damage to the plane will be discovered and Bob will be vindicated.
- Was remade for Twilight Zone: The Movie with John Lithgow as Bob, and with a far scarier-looking gremlin. This was lampshaded on an episode of 3rd Rock from the Sun that guest starred William Shatner, with the latter's character claiming he saw something on the wing of the plane during his flight and Lithgow's character exclaiming "The same thing happened to me!".
- Got a Spiritual Adaptation inThe Twilight Zone (2019) starring Adam Scott with the title Nightmare at 30,000 Feet.