Debut from 20-year-old director examines memory, reality and fear after Chiwetel Ejiofor accesses an infinite series of hidden rooms that all feel creepily askew

All the lonely people … where do they all belong? YouTuber Kane Parsons makes his feature directing debut with this icily brilliant and genuinely disturbing conceptual horror film based on his web series, and scripted by Will Soodik. There is something here of J-horror, the V/H/S found footage franchise, Dan Erickson’s Severance and Nathan Fielder’s The Rehearsal. It’s about people walled up in their own memories, imprisoned in endlessly remembered scenes from their past, or miserably perceived versions of their present existences in which they have become caricatures of themselves, gargoyle stars of their paralysed inner world of failure. Or perhaps the action of the film is not metaphorical in this or any other sense, and the “backrooms” of the title simply exist.

Chiwetel Ejiofor and Renate Reinsve give barnstormingly good performances as Clark and Mary; it is the early 90s and Clark is a failed architect, separated from his wife, and an alcoholic who to make ends meet self-hatingly manages a drearily and eerily vast discount furniture store, called Cap’n Clark’s Ottoman Empire. He does dumb TV ads dressed as a pirate while uneasily aware he should be a sultan to make the “Ottoman empire” pun work. He goes to see a therapist, Mary, a sad, gentle person who markets her own self-help audio tapes and is haunted by childhood memories of her abusive mother.

It was just a creepy picture on the internet. Now it’s the year’s freakiest film. Its 20-year-old auteur Kane Parsons and stars Chiwetel Ejiofor and Renate Reinsve take us through the terrifying labyrinth

Chiwetel Ejiofor has been on a lot of movie sets, but Backrooms was something different: a 30,000 sq ft labyrinth of apparently random corridors and chambers, all carpeted, fluorescent lit and decorated in the same sickly yellow wallpaper. It was so big that people were getting lost in it, says Ejiofor: “Especially on those first days. As you try to navigate your way around and you’re like: ‘I’m sure it’s this door, I’m sure that’s the way.’” He’s laughing at the recollection. “And you find yourself just back in the wrong corner of the whole studio and you’re like: ‘Get me some help!’”

This is kind of the point of Backrooms – the movie and the online phenomenon that spawned it. It’s a concept that takes some unpacking, but as the premise for a buzzy A24 horror freakout, you could summarise it as something like “The Blair Witch Project meets Severance” or “The Shining set in an infinite Travelodge”or maybe “the exact opposite of a Wes Anderson movie”. Comparisons fall short, partly because the Backrooms concept feels as if it’s come from another world – a parallel dimension, even. Ejiofor concurs: “There was stuff that we were doing by the end of the film that I was just like: ‘This is among the most bizarre things I have ever been involved in.’”