Jillian Bell, Jon Bass, Toby Huss, Marc Maron, Lynn Shelton, Michaela Watkins, Al Elliott.(Photo: Daniel Maurer)

What’s it like making a movie with legendary podcaster Marc Maron?

“Improvising with Marc is like the first 20 minutes of WTF before he brings out the other guest,” said co-star Michaela Watkins after the premiere of Lynn Shelton’s new film at South by Southwest.

Maron plays Mel, a—surprise—curmudgeon who owns a pawn shop in Birmingham, Alabama. When two women (Watkins and Jillian Bell) walk into the shop with a Confederate sword that supposedly proves the south won the Civil War, Mel and his mouth-breather sidekick (Jon Bass) team up with them to sell the item to someone who’s willing to shell out some serious cash. The mystery buyer seems to be a wealthy, racist conspiracy theorist—so you might say this film is topical.

Shelton hit on the idea when she passed an “amazing-looking pawn shop” in Los Angeles. “It just struck me that [Maron] should play a pawn shop owner in the midst of a comedy caper.”

As it so happens, many of Mel’s biographical details match up with Maron’s: He’s spent time in New Mexico, did heroin on the Lower East Side, and is having trouble getting over his ex. Maron’s old stomping grounds, Luna Lounge, aren’t mentioned, but the late Sidewalk Café gets a name check.

Shelton, who came up in the “mumblecore” genre of indie film, said she decided to harken back to her heavily improvised breakout films (Hump Day, My Effortless Brilliance, Your Sister’s Sister) by writing a “scriptment” of about 45 pages. Some of the scenes were written out, but that wasn’t the case with one of the film’s longer, more memorable sequences, in which a nutball white supremacist (played by Toby Bass) throws the sword sellers into the back of a van and takes them to his boss’s Tennessee estate.

The script said merely that the characters “get to know each other in the back of the van,” Watkins recalled. But the shoot was “nine hours of pure improv,” according to Shelton.

The director, who also plays Mel’s strung-out ex in the film, said “everyone was in tears at some point” as their characters told their backstories. But the hour-long takes proved to be a little too much for Maron, according to Shelton. “Marc was so angry. At the end of the day we were all hugging, exhausted, and just like, ‘Oh, we made it through.’ And like, ‘Where’s Marc?’ I texted him. He was just going to spew his rage at everybody.”

“I had to leave because I was going to make it bad for everyone,” Maron admitted, drawing laughter from those in the audience who were familiar with his hyper-neurotic shtick.

Maron, a standup who has expressed reservations about improv comedy on his podcast, said improvising for the film was “exciting,” even if he was uncertain at first. “At the beginning I didn’t feel like I was doing enough. I’ll be honest, I was like, ‘Why don’t they let me talk?’ And then I kind of worked that into my character; I’m like, ‘Alright. I’ll just be the cranky asshole who listens to all these lunatics talking all the time.’”

Which, come to think of it, is not unlike WTF. Add to which, Maron’s guitar noodling, which appears at the end of the WTF podcasts, was used to soundtrack the film. Shelton liked his licks so much that she ditched another composer to go with Maron. “Lynn decided, ‘Well, that seems like a good, cheap thing to do,” Maron said, to more laugher. “She says it was because it fit the character. I bought it; yeah, I bought that, but it was also a pretty reasonable way to track the movie.”