On a recent weekday afternoon in Manhattan, the director Owen Kline, 30, sat on a glass-doored conference-room couch. He wore a blue velour fleece adorned with a shiny brooch of a dancer-type figure. His reading glasses hung around his neck on a Croakies-like device. He looked gawky and, counterintuitively, very cool, which in turn made him feel very, specifically New York.

His parents are the actors Kevin Kline and Phoebe Cates. His sister is the indie music star Frankie Cosmos. When he was a teenager he played the little brother in The Squid and the Whale. His first full-length film, Funny Pages, produced by the Safdie Brothers and A24, is out August 26.

Shot on 16 millimeter film, it’s an aggressively prickly coming-of-age comedy about Robert, an aspiring cartoonist who abandons the suburbs to follow his dreams—and also to live in a basement boiler room with strange old men. (One of my favorite movie moments of the year is one of said men saying, “Dennis the evil menace with his slingshot.”) It’s one of those movies you only need to watch once to never forget. “How unpleasant this all is, from beginning to end, without being actually funny,” reads Deadline’s representative review. And then, a few sentences later: “I’m assured it’s destined to become a cult favorite.”

At a young age, Kline has a singular point of view and the confidence to try some weird shit. “Comedy is like that,” he says. “If you tether it to reality, you can make excuses for all these things that are unreasonable concepts.”

This interview has been edited for clarity and length.

WIRED: How did this movie start?

Owen Kline: Ten years ago I started to play around with these characters. Originally, I had written a comic version called “Robert in the Boiler Room.” Just figuring out who this kid is—that would want to go down there and be excited by this—was the starting point. I wrote the first draft of the script over 2014, 2015, and then it was years of trying to get interest and nobody even reading it. Then Josh Safdie read it.

How’d you originally connect with him?

I had known Josh since I was about 15, when he graduated from Boston University. The Safdie Brothers’ shorts just made an impact. When he moved back to New York, I held the boom mic for a couple of their projects and I acted for a short called John’s Gone, along with Benny [Safdie]. I just got in the weeds with those guys on the script, really figuring out a tone and a sensibility. They really helped me tease it out as a character study.

Eventually we were on set, and the first stuff we were filming was that basement stuff. It felt like we were starting where I had started with the comic, and it just set the tone for the rest of it. We just had such delirious fun spraying this glycerine all over these kids and old men. Sean Price Williams, the director of photography, kept saying more sweat, more sweat, we need to spray more sweat! We played around with smoke machines, to create a certain fog. We wanted it to feel like a steam bath. A geriatric steam bath.