When the final episode of Mork & Mindy aired on May 27, 1982, it brought to an end the unpredictable journey that helped to make Robin Williams a household name.

The character Mork first appeared on Happy Days four years before in an episode titled "My Favorite Orkan." The unusual idea to bring a space alien into the world of Fonzie, Richie and their friends came from Garry Marshall’s son.

“He was seven,” Marshall recalled during a conversation with the Archive of American Television. “I said, ‘Why don’t you watch?’ He said, ‘There’s no space people. I like space. I like aliens.’”

The show creator took the concept to his writers and suggested an alien be brought in for an episode via Richie’s dreams. Not everyone was excited about Mork from Ork’s arrival on Happy Days.

“We looked at each other like, ‘God, that’s the most horrible idea I’ve ever heard,’” Brian Levant, who was the story editor for Happy Days, later told Gizmodo. “But [Marshall] wants to do it, what do you do? So we drew straws to see who drew the short straw and had to write the script.”

Watch the 'Mork & Mindy' Opening Credits

Several actors passed on the role, including Dom DeLuise. Williams, a relatively unknown comedian at the time, convinced people the character would work.

“We were all there, and we saw one guy who embodied all three Marx Brothers, Chaplin, the Three Stooges, and William F. Buckley in the same body,” Levant said of Williams’ first run-through. “There was an intellect — and so bright and so fast – but creative.”

Mork’s episode of Happy Days aired on Feb. 28, 1978. It was an immediate hit, so when Paramount head Michael Eisner called Marshall months later asking for a new show idea, the producer’s mind naturally went to one place.

“I said, it’s called ‘The Mork Chronicles,’” Marshall told the Archive of American Television. “I had this idea, a man came down from space. and they said: ‘Nobody’s gonna know what chronicles means.’”

Marshall scoffed at the comment but eventually agreed to call the series Mork & Mindy. Pam Dawber, who had caught Marshall's eye in a failed TV pilot, would play Mindy. Not that anyone told her. “You’re not gonna believe what I am reading you out of Variety,” Dawber said her agent remarked as ABC announced its new fall lineup. “Monday night, 8 o’clock, Mork & Mindy starring Robin Williams and Pam Dawber.”

Watch Mork on 'Happy Days'

“Alien lives with girlfriend in apartment,” was how the show was described, something Dawber thought sounded “really stupid.” Still, after watching the tape of Williams on Happy Days, she quickly came on board. “It was so clear," she later told ABC. "He was adorable, he was so funny, and he just had it.”

Mork & Mindy arrived in September of 1978 and became an instant hit. Williams was hailed as comedy’s next big thing, gracing the covers of Time, TV Guide and People. But like a shooting star, the show soon began to burn out.

By season two, Mork & Mindy had dropped from No. 3 in the ratings to No. 27. In season three, they were No. 49. Most observers believed the show’s novelty had worn off. Behind the scenes, Williams was more interested in doing the kind of edgy comedy he regularly displayed in his stand-up routine, material that was far too shocking for network television. Efforts were made to revitalize the show, like bringing in Jonathan Winters as Mork and Mindy’s son, Mearth. Still, the ratings continued to sag.

In the spring of ‘82, the series finished shooting its fourth season, assuming they’d be coming back for more. As such, a cliffhanger was written into the season’s final episode, one that would have seen Mork and Mindy time-traveling in season five.

“It was going to be a semi-educational show, where Mork and Mindy traveling through time would meet with historical figures,” added Levant, who by this point had become an executive producer on Mork & Mindy. “We actually did a photoshoot for that, of [Mork and Mindy] standing with Abe Lincoln and Benjamin Franklin.”

There never would be a Season Five.

Watch the Final Episode of 'Mork & Mindy'

Late in the process, the cast and crew were informed that Mork & Mindy was canceled. They'd already filmed their episodes, and there was no a natural show conclusion. So, the producers opted to change the broadcast schedule of the final episodes. The three-part cliffhanger would be pushed forward, while “The Mork Report” would become the series finale.

The script revolved around Mork’s assessment of married life on Earth, as relayed to his heard-but-unseen alien leader, Orson. Mork determined that successful marriages had four main ingredients: honesty, respect, romance and compatibility. With each ingredient, viewers were given a scene from Mork and Mindy’s life that reflected the respective marriage keys. Though it may not have been groundbreaking storytelling, the device allowed viewers to get a final glimpse of what made Mork & Mindy so appealing in the first place: Behind the zany antics of this wide-eyed alien and his earthling wife was a lot of heart.

In a twist of fate, “The Mork Report” was the only episode that Williams directed. Even though it was never intended as the series finale, there was something poetic about the star taking control of Mork & Mindy's last TV moments.

“No one had ever heard of Robin Williams before, and this guy was a skyrocket,” David Misch, one of the show’s writers, told Gizmodo. “He was doing things no one had ever done on TV, and I think by the second, third and fourth seasons, people sort of knew them. Robin was just as brilliant, but he wasn’t as new, and I think that level of excitement [was gone]. And I don’t think the show came up to support him in the ways it could have, and so it sort of drifted away.”

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