In “Backrooms,” a creepy meditative dada horror trip in the what-is-reality? tradition of “Eraserhead” and “Skinamarink,” the director Kane Parsons turns our fears into a funhouse that’s got a lot of walls but no bottom. The central character, Clark (Chiwetel Ejiofor), is a divorced furniture-story owner who’s simmering with resentment over what a junk heap his life has turned out to be. Clark sees a therapist, Dr. Mary Kline (Renate Reinsve), and the two do a role-playing game in which they reenact Clark’s angry sob story of how his wife threw him out of the house. He’s now living in the store, which is called Cap’n Clark’s Ottoman Empire (he does TV ads for it in a pirate costume). It’s a big ugly place that sells cheap ugly furniture, and one day, when he’s trying to fix the store’s janky lighting, he’s drawn to a wall, then into the wall, which he passes right through.

On the other side of the wall is a vast empty room. It’s like a version of the store that’s been cleaned out, with musty carpeting, a ceiling dotted with rectangular fluorescent-light panels, and walls of faded urine-yellow. It’s connected to another room, and another, and another, and some of them contain stacked furniture or piles of laundry, and some are partitioned, with square holes that look like passageways. And the place just keeps going. Has Clark gone through a looking glass that’s going to lead him to a deliverance? Has he uncovered a mystery wrapped in a riddle inside an enigma? Or has he entered hell? Maybe all of the above.

“Backrooms” has a backstory that’s nearly as interesting as the movie. It’s not the first film to be spun out of a creepypasta concept (“Slender Man,” a studio release, came out in 2018), but it might be the first to speak in the language of Internet memes, to channel the very form of metastasizing web horror. The Backrooms started off as a single spooky photograph that was snapped during the renovation of a former furniture store in Oshkosh, Wisconsin. The concept was then expanded, on a 4Chan thread, by users, but it remained a vision of hell as infinite abandoned office space until 2022, when 16-year-old Kane Parsons took that premise and expanded it into an intricate series of short films on YouTube; the series became a sensation.

In the Backrooms films, the camera wandered through room after room (it was like a movie set without end), the images shot through with degraded VHS grain. There was a “Blair Witch” aura to it all — the found-footage dimension, with the handheld camera that the camera person never puts down, even when running, and the whole hint of “What lurks behind the next corner?” But it was also a seminal example of the “liminal space” aesthetic: images of empty or abandoned spaces that feel forlorn and vaguely haunted and have the quality of a real-life portal. The original liminal space might almost be the shots of empty hotel corridors in “The Shining,” a film that I’ve always found to be far spookier in its audio-visual design than in anything else about it.

Based on the popularity of the Backrooms series, Parsons got an offer from A24 to spin a horror movie out of it, and given that he’s only 20 years old, that makes him sound like the Orson Welles of viral cinematic crossover. (So does his first name!) And maybe he is. “Backrooms,” drawing on Parsons’ following, could turn out to be the first experimental horror film that makes $25 million in its opening weekend. Parsons, in his feature directing debut (the script is by Will Soodik), proves to be a wizard of mood who shares the early David Lynch’s love of industrial cosmic sound design, and also Lynch’s fixation on the mysteries of electricity. Parsons wrings true terror out of the sense of being enclosed, in what feels at times like it could be some infinite version of a serial killer’s lair.

As an atmospheric freakout, “Backrooms” is extraordinarily effective. You sit back and settle into the enigmas and the grunge textures, knowing that the movie is going to keep raising your eyebrows. The sensation of moldering dread hinges on the prospect that something awful is lurking inside those musty yellow rooms, kind of like the monster that pops up in Lynch’s “Inland Empire” (another progenitor of The Backrooms). And Parsons, in his too-refined-for-jump-scares way, delivers those monsters — or, at least, a few tormented figures of twisty-headed horror. There’s a towering demon version of Cap’n Clark, as well as humans who look like they have several faces crumpled into themselves. What are they? Maybe they’re us.

Chiwetel Ejiofor, who is such a great actor, is the perfect presence to have at the center of all this. His morosely bearded, boozing Clark is a man whose broken-down life doesn’t make sense to him, and as he’s drawn into the backrooms, he communicates — and inculcates in the audience — the feeling that he’s searching for a catharsis of meaning, even if it turns out to be a nightmare (which, of course, it does). 

For all the spooky vividness of its imagination, is “Backrooms” a good movie? It’s a film of suggestion and down-the-rabbit-hole darkness, like a haunted-house thriller renovated into a shivery poem. It may alienate anyone expecting a conventional fear ride. Parsons, for everything he shows you, leaves you with the sensation that the real horror may be just out of reach — which, in its way, is what makes the liminal-space aesthetic a form of cool. But there’s no denying that Kane Parsons is now the master of it. Going forward, it will be fascinating to see how he fills those spaces.