William Shatner Pulled A Cruel Prank On Set Of The Twilight Zone

The opening narration to "The Twilight Zone" episode "Nightmare at 20,000 Feet" (October 11, 1963) states that Bob Wilson (William Shatner) has just been discharged from a sanitarium, finally having (mostly) recuperated from a nervous breakdown experienced on an airplane six months earlier. He is about to get on a plane again for the first since his breakdown, and his wife Julia (Christine White) is wary that flying may trigger another severe panic attack. Bob assures her that he may be nervous, but that he should be able to survive. 

Of course, nothing natural or easy happens in the Twilight Zone. Bob peers out the window and sees, on the wing of the plane, a large furry gremlin (Nick Cravat). It sees Bob as well. When he calls a stewardess for help, the gremlin vanishes, able to lift off into the rainy night sky. When Bob is looking, however, it reappears and begins pulling on the plane's metal panels, poking at the circuitry inside. It will sabotage the plane and kill everyone on board if Bob doesn't do something, but what can he do? And is the gremlin a hallucination, brought on by his nerves? 

"Nightmare at 20,000 Feet" is perhaps the most famous episode of "The Twilight Zone," partly because of the novel premise (written by Richard Matheson, based on his 1961 short story), but largely because of the appearance of a pre-"Star Trek" William Shatner. The young Canadian actor had already been acting professionally in film and TV for a decade, so he appeared on set self-assured and relaxed. Indeed, according to episode director Richard Donner, in an interview with the Academy Television Foundation, Shatner decided to play a "cute" prank by making his director think he had plummeted to his death.

According to Richard Donner, the shoot on "Nightmare at 20,000 Feet" was, well, a nightmare. In order to make it look like a plane was up in the sky, the entire airplane set was hoisted high above the ground. Donner described the process thus: 

"It was a tough shoot. It was an airplane ... in a tank, elevated way off the ground. We had to climb up. We had massive wind machines. We had lightning machines. We had rain machines. We had effects machines working because we had to also turn the engines. There were no computers or anything to do it. Everything had to be live. Everything had to be synced."

Because everything was so technically intense, and because the shoot had a very tight schedule, Donner said he like to keep the tone on the set light and relaxed. He felt that everyone would do a better job if they were content and jovial; being stressed out and overworked wasn't a great way to make TV. Everyone was exhausted on the set of "Nightmare," but everyone was having a good time. Donner himself, meanwhile, was mainlining coffee, trying to stay awake and just make it to the end. 

It seems that the jovial set was perhaps a little too much leeway for Shatner and actor Edd Byrnes (from "77 Sunset Strip"), visiting the set that day to say hello to his wife, actress Asa Maynor (who played the episode's flight attendant). It seems that there was an articulated dummy on set that was too tempting for Shatner and Byrnes not to do something with. When Donner was busy downing coffee, the two actors schemed.

Donner recalled the prank well. He said: 

"I hear this screaming and yelling and everything, and I run back and I see [Byrnes and Shatner] fighting. And then they went behind the body of the airplane, and all of a sudden, I see Shatner fall off the wing and fall all the way to the bottom — it's concrete — and he hit the ground. [...] I thought he was dead, man. And I came running up and I grabbed him, and then everybody's standing around laughing."

It seems that Shatner and Byrnes had choreographed a fight on the wing of the plane set wherein Brynes pushed the articulated dummy off right when Donner was looking at them. Ho, ho, it is to laugh. Donner panicked when he thought his star had died, but relaxed when he found it was just a prank. He admitted, however, that it wasn't because Shatner was alive that he was relieved. The shoot was so stressful, and the timeline so tight, he was merely happy that he wouldn't have to recast the part and begin from square one. He said:

"Honestly, my first reaction was, 'Don't tell me I have to shoot the whole show over again.'"

No one died, the shoot went off without a hitch, and TV history was made. Indeed, the story was so popular that it was remade by director George Miller (with John Lithgow starring) for 1983's "Twilight Zone: The Movie." When the series rebooted in 2019, Adam Scott starred in a version directed by Greg Yaitanes. That episode upped the titular altitude to 30,000 feet and featured a haunted MP3 player instead of a gremlin. 

Matheson once told me that he preferred the Shatner version, although he thought the gremlin looked like a panda.