William Shatner explains why his classic 'Twilight Zone' episode continues to frighten airplane travelers

It's been nearly 60 years since William Shatner flew the unfriendly skies in "Nightmare at 20,000 Feet" — one of the most famous installments of Rod Serling's seminal horror series, The Twilight Zone. Directed by Richard Donner, the episode features the Star Trek icon as Bob Wilson, who is flying home with his wife Julia (Christine White) after being discharged from the sanitarium, where he's been recovering from a nervous breakdown. But in the middle of the flight, he notices a strange figure on the wing of the plane that only he can see. What he's witnessing is a gremlin attack — and not of the "don't feed them after midnight" variety.

Premiering on Oct. 11, 1963, "Nightmare" is the first episode many think of when The Twilight Zone theme starts playing. And to this day, Shatner still finds himself gremlin-spotting when he gets on an airplane. "I used to play that game with my kids," the actor tells Yahoo Entertainment with a laugh during a conversation about his new memoir, Boldly Go. "They'd bring the hostess over and, and I'd be looking at that window and everybody would roar with laughter." (Watch our video interview above.)

That's not how Shatner felt when he originally filmed the episode, though. Instead, he spent much of his time on set concerned that "Nightmare" would be a career-killer. At the time, the Montreal-born Shatner was a regular supporting player in American television, with a résumé that included such shows as Naked City and Alfred Hitchock Presents. In fact, "Nightmare" was his second appearance on The Twilight Zone, having previously starred in the 1960 episode, "Nick of Time," as one-half of a honeymooning couple who run afoul of a devilish fortune-teller machine. (Both episodes were penned by Richard Matheson, author of the hugely influential vampire novel, I Am Legend.)

"Nightmare" was a more ambitious episode than the small-scale "Nick of Time," which also meant that The Twilight Zone's budgetary restraints were more evident, at least to Shatner. Specifically, he found himself skeptical of the episode's gremlin, who was played by stuntman Nick Cravat in a costume that didn't exactly strike fear into the star's heart. "What was amusing was the acrobat who was in a little furry suit on the wing of the [plane]," Shatner says now. "There were times when I looked at him, and I thought: 'This is maybe the worst thing I've ever done!'"

Still, when you're a working actor that's a few years off from his big break — Star Trek: The Original Series wouldn't take flight until 1966 — you're usually just glad to be collecting a paycheck. "I was so filled with gratitude that I was being paid and could pay my bills," Shatner says of how he offset his concerns about the creative quality of the episode. "The fact that it might be beyond laughable never occurred to me."

Donner, of course, would later go on to direct blockbusters like Superman: The Movie and The Omen, but Shatner says that the young director didn't exactly have the time on the "Nightmare" set to talk to him about his artistic approach. "The directing was like, 'Why don't you say that louder or faster?' I don't think that [art] occurred to anybody. I think what was occurring to people was get the shot before the sun set!"

While Shatner spends the majority of "Nightmare" frozen in his chair, the actor — whose fisticuffs as Captain Kirk are still unmatched in sci-fi TV history — did get physical in the climax, when Bob shatters his airplane window to take a shot at the gremlin. "I've done a lot of stunts and taking terrible risks … putting myself through a window was nothing," he says modestly. "Sometimes I've done foolish things, and I don't know why. I don't know what I'm proving to myself or anybody else, but it never occurs to me that I'm going to get hurt."

"I was on the West Coast one time, and we were shooting a motorcycle sequence," Shatner continues, recalling one particularly dangerous stunt. "I had to jump the motorcycle, and I came to the lip and stopped. The stuntman got on, jumped the motorcycle and broke his back! It could have been me."

Instead of tanking Shatner's career, "Nightmare at 20,000 Feet" ended up entering the pantheon of all-time great episodes of television. It's been referenced and parodied countless times in everything from Sharknado to The Simpsons, and so thoroughly defines The Twilight Zone that it's been remade twice in subsequent franchise continuations. John Lithgow played Shatner's role in the George Miller-directed "Nightmare" installment that appeared in 1983's Twilight Zone: The Movie, and Adam Scott played a variation on the part in an episode of the 2019 Paramount+ series overseen by Jordan Peele.

For Shatner, the longevity of "Nightmare" can be chalked up to one very simple explanation: Flying still freaks many people out, even if the idea of sitting in a metal tube thousands of miles up in the air strikes others as banal. "One of my daughters has a phobia of flying," he says. "When we go on family trips, she sits beside me … and I'm explaining [what's happening] to her. So there are people who are fearful of flying when there's no reason. In all the flying I've done, I may have had a lightning strike or there was a loud bang, but nothing approaching the 'I'm gonna die here' feeling. So I think that's what the show fastened onto — our fear of flying."

— Video produced by Kyle Moss and edited by Jason Fitzpatrick

The Twilight Zone is currently streaming on Paramount+.