Crispin Glover delivered one of the most notorious appearances in late-night television history on July 28, 1987. Whether it was genius or cringe-worthy continues to be debated.

The eccentric actor had seen his star rise thanks to a scene-stealing role in 1984’s Friday the 13th: The Final Chapter, followed by a turn as George McFly in Back to the Future.

A scheduled appearance on Late Night With David Letterman was meant to promote his new film, the dark indie drama River’s Edge. Instead, Glover delivered a bizarre and confusing interview without any clear purpose or direction.

From the moment Letterman introduced his guest, Glover appeared distressed. He wore a clashing attire of striped pants with a print, a short-sleeve shirt, black platform shoes and an off-center wig. “I’m having a very good summer,” Glover awkwardly mumbled early in the interview, while squirming in his chair.

Seemingly suspicious of what was unfolding in front of him, Letterman tried lobbing some softball questions toward his guest, but Glover didn’t engage. Instead, Glover embarked on a nonsensical rant about how he was portrayed in the media.

“The press, they can do things. They can twist things around,” Glover declared before pulling newspaper clippings from his pocket and frantically reading stories about himself.

“Paul, you got anything to add here?” a befuddled and unamused Letterman asked sidekick Paul Shaffer, who quickly shook his head and said “No.”

As Glover continued reading press clippings, Letterman again turned to his bandleader. “Paul, is this the first time you’ve seen another man drown? Is this the first time you’ve seen another man die?”

Unimpressed with what was happening on his show, Letterman tried to rein in Glover’s antics. “You seem to be distraught,” Letterman suggested. “People try to make me sound a lot weird. I’m strong. You know, I’m strong,” Glover replied, pulling up his sleeve and flexing his bicep. Things only got weirder from there. Glover offered to arm wrestle Letterman, who declined. Glover then karate kicked within inches of the host’s face, which finally convinced Letterman to end the segment.

“I’m gonna go check on the Top 10,” Letterman declared, walking off the stage and leaving his guest briefly alone before the show cut to commercial. When Late Night returned from break, Glover was gone, and Letterman was back behind his desk.

“I think that’s the first time that we’ve been doing this show that a guest actually tried to kick me,” Letterman glibly remarked, referring to Glover as "some goofball, some dork from wherever." Letterman admitted that Glover "came very close to denting my head with those giant shoes, so I thought, 'I don't need that. I'm 40. I went to college. That is not how I want my life ended."

Watch Crispin Glover on 'The Late Show With David Letterman'

Even in an era before social media, talk of Crispin Glover’s Late Night appearance quickly spread. Many questioned whether the notoriously unconventional actor had been playing a part. Some thought Glover was satirizing. Others theorized that he may have been on drugs.

Letterman only further fanned the flames when he opened his next show with a sketch describing Glover’s appearance as a bad dream. “Dave, that was no dream. He was on the show,” Shaffer explained to Letterman, before promising it’d never happen again because he and stage manager Biff Henderson followed Glover back to his hotel. “We smothered him with his mattress. He’s dead,” Henderson remarked, much to Letterman’s delight.

Interestingly, Glover returned to Late Night only a few weeks later and was much more jovial. He was vague, however, when asked about his previous antics. “I wanted it to be this interesting kind of, a thing that would happen that people would find interesting,” Glover explained through laughter.

He ended up playing the role of Rubin Farr in the 1991 comedy Rubin & Ed, and Farr's demeanor and appearance recalled Glover's Letterman interview. This led many fans to speculate that the method actor was simply in character on Late Night. Still, in the decades since his swinging foot came incredibly close to Letterman's face, Glover has continually avoided directly answering questions about that night.

“The thing that I say in media, which we're in right now – what I always answer is, ‘I neither confirm nor deny that I was ever on the David Letterman show.’ Which, of course, there's a sense of humor to it – you can make what you want,” Glover told the Huffington Post in 2012. “When I started acting, my concept about publicity ... my interest was just to be an actor. I was never really that comfortable with publicity.”

Glover admitted in a separate interview with Interviewing Hollywood that he enjoyed the fact that no one knew what to make of his behavior.

“I like there to be an air of mystery. If I just said exactly what it is, it’s not interesting. It doesn’t let people think about things,” he said.

“I think people still think that this person could either have something wrong with them mentally or that there was some kind of drug influence. There’s all kinds of suppositions as to what it could be. Or that, who knows what it could be? People do suppose different things. I’d just rather let them suppose.”

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