In a video from Emerald City Comic Con — which was taken in 2013 but only recently came to light online — Stewart told the crowd that while he was working on the 1984 sci-fi epic, he had no idea his co-star Sting was a famous musician.

After being asked what it was like to work with Sting, Stewart, who played Gurney Halleck, began by saying he was actually miscast in the film. He doesn't get into specifics, but told the crowd, "The fact is David Lynch thought he had cast somebody else."

Stewart then talks about his hilarious on-set interaction with Sting, who played Feyd-Rautha in the film based on the 1965 novel.

"Music, at least popular music, has never played a big part in my life," Stewart began, setting the scene. "I had never heard of Sting. That's how isolated I was from the music world."

He may not have known who Sting was, but Stewart said he realized the man must be someone important, because people were going nuts when he arrived on set.

"I heard he was a musician ... and so the second or third day we're just hanging out on the set, just him and me, and I say, 'So, you're a musician?' And he said, 'Yup.' And I said, 'What do you play?' And he said, 'Bass.' And I said, 'You know, I've often wondered what is it like carrying that huge thing around everywhere you go,'" Stewart said.

He continued, laughing, "And God bless him, he said, 'No, bass guitar.' And I said, 'Are you a solo artist?' And he said, 'No, I'm in a band.' And I said, Oh, what kind of band?' And he said, 'The Police,'" Stewart recalled. "Folks, I said, 'You play in a police band?'"

That line sends the audience into hysterics while Stewart just looks away, grinning to himself.

A Dune reboot is still being developed, with Blade Runner 2049 filmmaker Denis Villeneuve attached to direct.