Though it’s been more than 50 years since it left the air, Rod Serling’s The Twilight Zone continues to be a benchmark for all the science fiction and fantasy series that have followed. Shows like Lost, The Leftovers, and Under the Dome often draw comparison to Serling’s densely-populated fifth dimension of moral quandaries and supernatural occurrences. Naturally, the show’s history has a few curious footnotes. We’ve unlocked the door to some of the most intriguing.

1. Serling vs. Bradbury

Though Serling was contracted to write most of the scripts for Zone during its five-year run from 1959 to 1964, it was impossible to tackle every single episode. At first, the multiple-time Emmy winner wanted to give new writers a chance to break into the business. But when the show received over 14,000 submissions—most of them either unread or deemed unsuitable—he learned to depend on authors like Richard Matheson, Charles Beaumont, and George Clayton Johnson for story springboards or full scripts.

Serling also sought out the talents of sci-fi giants like Arthur C. Clarke and Ray Bradbury. Clarke was unavailable, but Bradbury wrote several scripts, only one of which made it to air: an adaptation of his short story “I Sing the Body Electric.” Serling would go on to say that Bradbury’s work “seems to lend itself to the printed page, rather than spoken language.” Bradbury, possibly nursing a bruised ego, accused Serling of the capital crime of writing: plagiarizing stories. An offended Serling told interviewers he admired Bradbury immensely, but it’s unknown if the two ever reconciled before Serling’s death in 1975.

2. The Episode That Won an Oscar

When Serling’s budget for the series tightened in the fifth and final season, he decided on an unusual cost-cutting measure: the writer paid $10,000 (by some accounts, $25,000) for the rights to broadcast An Occurrence at Owl Creek Bridge, a French short based on the Ambrose Bierce story about a Confederate sympathizer who escapes the hangman’s noose at the end of the Civil War. No dubbing was needed: the short was virtually silent, and its haunting cinematography was a perfect fit for the show. The year prior, it had won an Oscar for Best Short Subject. Bierce’s story was also adapted into an episode of the other popular anthology of the day, Alfred Hitchcock Presents, marking the only time the two series used the same source material.

3. Tossing Shatner off the Plane

Director Richard Donner still had his feature career in front of him (Lethal Weapon, Superman: The Movie) when he worked on “Nightmare at 20,000 Feet,” about a man (William Shatner) getting on a plane after recovering from a nervous breakdown. Inevitably, Shatner wigs out when he sees a gremlin on the wing tearing the guts out of the engine, and is unable to convince his wife or attendants of the danger.

The episode was shot in an empty water tank, with the plane roughly thirty feet off the ground. Produced in the show’s typical hurried pace of three days, Shatner and actor Edd Byrnes decided to add to Donner’s stress by staging a mock fight on the wing. As Donner looked on, the two grappled before throwing a Shatner-sized dummy that crashed to the concrete below. The director was horrified, but later joked his first thought was that they’d have to reshoot with another actor. (Serling himself didn’t fare as well with another “Nightmare”-related prank. He once stuck a picture of the monster on writer Richard Matheson’s window seat; the propellers blew it off before Matheson could see it.)

4. Six Dimensions

When Serling recorded his famous opening narration for the pilot episode in 1959, he began by intoning that there was “a sixth dimension” to explore. A CBS executive heard it and asked the writer why he had skipped a fifth dimension—weren’t there only four? Serling, puzzled, hadn’t really considered it. “Oh,” he said. “Aren’t there five?” The narration was re-recorded before any angry letters from physicists poured in.

5. J.J. Abrams’ Felicity Homage

Countless Zone parodies and tributes have aired over the decades, but writer/director J.J. Abrams wanted something bolder than a bad Serling imitation. For a 2000 installment of his twentysomething drama Felicity, Abrams filmed an episode that put the cast in a dreamscape of paranormal events. To mimic Zone’s trademark black and white visuals, Abrams hired one of the show’s original directors, 77-year-old Lamont Johnson. Critics praised the effort. (Abrams, an admitted Serling fan, bought the writer’s last script, The Stops Along the Way, in 2013, with an eye on producing it as a limited series.)

6. Your Host, Desi Arnaz

While CBS deliberated over Serling’s pitch for a primetime fantasy anthology series in the late 1950s, producers of the network’s Desilu Playhouse had pulled his original pilot script, “The Time Element,” from storage. In it, a man sees a psychiatrist with recurring nightmares where he tries to warn others of an impending attack on Pearl Harbor; at the climax, he disappears, with the doctor being told he died during the attack some 15 years prior.

After the hourlong drama unfolded, Arnaz came out to address the audience directly, offering his take on the ambiguous ending. “We wonder if Pete Jenson did go back in time,” Arnaz pondered. “Any of you have any answers? Let me know.” Arnaz’s clumsy wrap-up would later make Serling’s deft touch look stellar in comparison.

7. Humoring Producers

Though prolific and cutting in his veiled social commentary, Serling’s one weakness as a writer may have been trying to wring comedy out of his erudite characterizations. In “Cavender is Coming,” an angel is sent to Earth to help Carol Burnett find happiness. (The moral: Even in a humdrum existence, she had it all along.) CBS thought this would make a fine pilot for a sitcom, and so for the first and only time in Zone’s run, producers added a laugh track. Viewers did not embrace the social enforcement: “Cavender” never made it as a series, and the canned laughter was removed for syndication and home video release.

8. God Complex

Though he spoke fondly of Serling through his entire career, Zone teleplay writer Richard Matheson (“Steel,” “The Invaders”) found one mandate puzzling: According to Matheson, only Serling could use the word “God” in his teleplays. It was off-limits to the rest of the writing team. “I used to get ticked off at Rod because he could put ‘God’ in all his scripts,” Matheson said. “If I did it, they’d cross it out.” Matheson never asked, and was never told, the reason behind the rule. Chalk it up to a mystery worthy of The Twilight Zone.