For this week’s Infinite Scroll column, Alex Barasch is filling in for Kyle Chayka.

Horror is a genre of upstarts. Many of its strangest, most striking films, from “The Night of the Living Dead” to “The Blair Witch Project,” come from first-timers working on shoestring budgets—and these days the first-timers can be found, increasingly, on YouTube. In 2018, Kyle Edward Ball launched a channel where he released videos based on users’ descriptions of their nightmares. The entries, with such deceptively simple titles as “sound in the hall” and “grandma,” are lo-fi, no more than a few minutes each; they dial into dream logic, primal dread, and a viewer’s instinct to fill in the gaps, a grainy shot of a bedroom door inviting the question of what’s waiting on the other side. The shorts paved the way for Ball’s experimental film “Skinamarink,” which became a word-of-mouth phenomenon in 2022. That same year, a teen-ager named Kane Parsons began posting a series of creepy, atmospheric clips set in the Backrooms, an endless, harshly lit liminal realm drawn from the crowdsourced mythology of the internet itself. (The look and vibe influenced the TV show “Severance.”) A24 is now producing his début feature, aptly named “Backrooms.” The studio has also partnered with Danny and Michael Philippou, who were vloggers before they broke out with “Talk to Me,” a movie that intimately understands the perils of a viral challenge: the inciting incident is a demonic possession documented on a dozen smartphones. Curry Barker, meanwhile, established himself on YouTube as a sketch comedian before playing a murderous influencer in “Milk & Serial,” an hour-long slasher which he uploaded directly to his channel; his first full-length film, “Obsession,” will be released by Focus in May. And then there’s “Iron Lung,” the new movie from Mark Fischbach, which reached theatres in a far more unorthodox way.

When Fischbach started shopping around “Iron Lung”—a self-funded horror film based on an indie video game of the same name—it was effectively turned down by every major U.S. distributor. He reasoned that the thirty-eight million YouTube followers who know him as Markiplier could fill at least fifty theatres, and decided to negotiate a limited release himself. After he announced the plan on his channel, noting that fans could also request showings at their local multiplexes, they did so in such numbers that some business owners apparently suspected bots. Fischbach and his wife fielded queries and handled bookings directly; Regal Cinemas’ head of content, Brooks LeBoeuf, lobbied by Markiplier subscribers on his own staff, eventually agreed to carry “Iron Lung” nationwide. Other chains followed. In the wake of interest from abroad, Fischbach had to text the game’s developer to check that he had international rights. Soon, “Iron Lung” was slated for four thousand screens. Since it opened, on January 30th, it’s earned upward of forty million dollars—trouncing another, far costlier horror movie of a sort, “Melania.”

Unlike other YouTube creators turned filmmakers, Fischbach made his name online not through sketches or shorts but via “let’s plays”: a genre in which someone runs through a video game for an audience, their face visible in a corner of the screen as they narrate and react to the proceedings. Fischbach rose to fame navigating indie horror games like Amnesia: The Dark Descent, usually with jokey commentary punctuated by jump-scare-induced exclamations of “fuck!” He played Iron Lung in 2023, and the film he’s produced is remarkably (and perhaps regrettably) faithful to his experience with the source material. The movie’s opening voice-over explains an event known as the “Quiet Rapture”: the day the stars winked out and whole planets disappeared, leaving a handful of humans to settle on a distant moon. Fischbach plays one of the survivors, a convict deemed expendable and thus dispatched to explore an ocean of blood in a rickety submarine. For long stretches of “Iron Lung” ’s hundred-and-twenty-seven-minute running time, he’s the only person onscreen, attempting to reach a series of coördinates and taking X-ray images of what lurks beneath the depths. Seeing a skeletal creature materialize in the darkness is ominous; returning to the site to find that it’s disappeared is even worse. As his oxygen supply dwindles, he searches for answers and sketches out a crude map with such landmarks as WEIRD TUBES and ALIEN SHIT. Occasionally, we get hints of a larger, more complicated universe. Mostly, we hear Fischbach saying, “Fuck that,” “Fuck me,” or “I’m fucked.”

As a movie, it’s impenetrable. As a long-form let’s play, it starts to make more sense. Fischbach has tailored the structure to his native medium in more ways than one: as he told Variety, “Hopefully, people will have a good time, but leave it saying, ‘What just happened? I might need to see that again to really get an idea, or watch someone do a breakdown of it later.’ ” True to his wishes, videos from fellow-YouTubers with such titles as “Iron Lung Lore Explained in The Simplest Way Possible” and “The TERRIFYING Iron Lung Monster EXPLAINED!” quickly materialized. “Iron Lung” ’s jury-rigged theatrical run has been extended, and Fischbach’s fans, by and large, have loved it. A comment posted the day of the film’s release beneath his years-old video about the original game, asking “Who’s here after he did an IRL playthrough,” has nearly a hundred thousand likes.

That “Iron Lung” isn’t very good is almost beside the point. The underdog narrative around the movie is infinitely more appealing than the one onscreen: an aspiring filmmaker poured years of his life and his own money into a movie that’s become a hit. He broke down in tears while thanking his fans for their support. Having made back fifteen times the production costs at the box office, he’s giving bonuses to his scrappy crew. But a win for the little guy is also a win for the much bigger guy. As Fischbach put it recently on the industry podcast “The Town,” “YouTube is the thousand-pound monster lurking over everyone’s shoulders.”

YouTube’s C.E.O., Neal Mohan, has declared “Iron Lung” ’s success evidence of a “new era in Hollywood.” An audience transferring so decisively from one medium to another is almost unheard of: just try naming the last YouTuber (or TikToker, or Instagram influencer) who has made it as a leading man. Fischbach had the benefit of an unusually active fandom—one that had been getting steady updates on this particular project for years—and of working within a genre optimized for such an outsized hit. It’s unlikely that anyone else could reliably replicate the outcome. But YouTube, which has around 2.5 billion monthly users and last year generated some sixty billion dollars in revenue, is already the No. 1 streaming platform in the world. Studios are now contending with it in a different way—and even Netflix and Amazon, themselves born out of Big Tech, recognize it as an existential threat, poaching vloggers and video podcasters in a bid for their audiences’ attention. (MrBeast, who hosts the competition show “Beast Games” on Prime, and Jake and Logan Paul, who engage in stunt fights live on Netflix, are among the more unfortunate exports.) Mohan might still prefer that directors come to him, rather than have YouTubers “graduating” to the traditional film industry. As another YouTube executive told Bloomberg, the goal is to get to “a place where anybody who’s taking a movie to Sundance might look at us as a potential distribution platform or an opportunity to go direct to consumer.”

Fischbach himself thought of “Iron Lung” ’s fate in terms of the war between YouTube and Hollywood. In one video, he talked about how “there is something fundamentally broken with the movie industry,” even as “there is a want to go see movies.” During the film’s first weekend in theatres, he started a live stream, entitled “ACTUAL EMERGENCY MEETING!!,” urging fans to help maintain a shrinking box-office lead over Sam Raimi’s starry, forty-million-dollar horror-comedy “Send Help,” which had opened the same day. (In the end, “Send Help” narrowly outgrossed “Iron Lung,” though the latter sold more tickets.) Fischbach framed it as a way for a tiny indie to give Disney, which had distributed “Send Help,” a run for its money.

There’s irony in Fischbach seeing Raimi, who got his start making home videos in which he and his friends aped the Three Stooges’ antics, as the establishment filmmaker to beat. In 1981, when Raimi completed “The Evil Dead”—a gory, gonzo story of demonic possession, made for a few hundred thousand dollars—it, too, was roundly rejected by American distributors. It’s since become a cult classic. In a 1982 interview about the making of “The Evil Dead,” Raimi, still in his early twenties, sounded a lot like the YouTube generation, dismissing “the films that are glutting the market” as “re-creations of the ones that have made money.” But he was optimistic about the future of horror movies. “There’ll always be a market for them,” he said. “There always has been.”

Forty years on, Raimi’s view has been vindicated. Where romance and comedies cycle in and out of fashion, horror is the only genre that consistently gets people into theatres, even amid a post-pandemic decline in moviegoing. We never lack for fresh phobias to metabolize and exploit—witness the number of horror movies made lately about social media—and there’s a particular catharsis that comes with being scared together in a darkened room. Crucially, these films can also be made cheaply: the suggestion of a monster is often scarier than an expensive C.G.I. rendering. Studios have long since discovered that producing or acquiring one for a modest sum can yield a high return on investment. Perhaps the most dramatic case study is “Paranormal Activity,” a 2007 indie about a couple who suspect they’re being haunted and set up a camera in their bedroom to investigate, which was shot for fifteen thousand dollars and went on to gross nearly two hundred million. For every schlocky, derivative entry, there’s one that endures.

“Iron Lung,” originally slated for a one-weekend domestic release, is still in theatres around the world—but Fischbach is already back on YouTube, uploading more let’s plays. In the comments, some fans have begun to speculate about which game might be the seed of his next feature-length endeavor. Others are negging him about his big-screen accomplishments. “Wow the director of Iron Lung made a youtube channel,” one user wrote. “Hope it goes well for him.” ♦