Here’s a thriller that Maurice Escher could have production designed, with Salvador Dalí decorating the sets and Stanley Kubrick behind the camera directing.

Not that Youtube phenom turned horror filmmaker Kane Parsons is the new Kubrick. But in turning his “Backrooms” found footage horror video series into a feature film, he and his production designer Danny Vermette (“Longlegs”) and art director Alan Derksen summon up not just cinematic horror imagery of the past, but of the most disturbing painters in the canon.

A visual essay in the sinister possibilities of a minimalist unknown becomes something deeper with nightmarish echoes of Heironymous Bosch and Dalí pasted on a yellow on yellow settings that could have been inspired by Mondrian.

This summer’s “Blair Witch Project” horror phenomenon is about a stressed, divorced furniture store owner who stumbles into an alternate reality by stepping through the walls of the basement of his bland ’90s surburban warehouse store.

Clark (Chiwetel Ejiofor, bringing the “real”) never seems to have any customers, which only adds to the bitter edge his drinking has taken on.

“Cap’n Clark’s Ottoman Empire” is a badly-named “cheap particle board” furniture warehouse store which Clark tries to advertise with DIY commercials of himself dressed as a furniture pirate. The whole “pirate” or “sultan” branding doesn’t work and even his young dead-end employees (Lukita Maxwell and Finn Bennett) get that they don’t “get it.”

It’s only with his therapist (Renate Reinsve of “Sentimental Value” and “The Worst Person in the World”) that Clark gets into the reasons for his anger. He lost his house in a divorce to his perpetual law-student wife.

“I hurt people,” he confesses. “It’s just the way I”m wired.”

Role-playing the “big fight” that ended his marriage doesn’t help, and we wonder if published author Dr. Mary has a clue about how to get Clark “forging a new path” to better mental health.

The dude’s sleeping in his furniture store, after all. He’s got almost nowhere to go but up. But will he?

Something about this yellow wallppaper and yellowish carpet milieu of vast rooms, empty sections, cubicles with no one in them, wonky wiring and PA and CCTV systems gives him and us as viewers the creeps.

Poking around in the basement has him poking a wall because he hears something, and then freaking out when his arm and indeed his entire body go right through it.

Horror films that cast really good actors are the ones that manage the proper level of “This can’t be happening” shock and awe at what transpires. Clark absorbs the shock. Then he “explores” this beyond-the-basement-wall realm — mysterious piles of what looks like furniture, but “make no sense” as chairs or desks or what have you.

Half-buried manikin parts protrude, Dalí style, out of the floor. An advertising standee with a pirate on it chirps away greetings in a parade of languages. Walls recede into some pointed forced perspective and shafts and tunnels present themselves to Clark, who knows there’s someone or something in there with him. It’s just that he can’t help but come back.

Trying to explain to his therapist this “New York Subway System…massive” maze of rooms and corridors gets him nowhere. And rounding up his two employees to join him for this “expedition” to video what they find seems a mistake. It always is.

“Backrooms” is primarily a triumph of horrific tone, with a handful of grim and gruesome shocks to sate viewers who like their horror violent and bloody.

The look and the psychological mystery at the heart of it feed into the chill that sets in early and rarely leaves your mind. Horror conventions such as a character being snatched out of the frame and “Slenderman” like figures — and a dwarf — are tucked into this “Everything Everywhere All at Once” universe of an underworld.

The finale is entirely too conventional and pat to fit the general weirdness of all that’s preceded it. And as we ponder the puzzle what connects these people to that place — literal or mental — we have to consider what indie cinema icon Mark Duplass might be playing and what Reinsve is getting at as we see and hear her struggle to emote or even hit the right word emphasis in sentences in English.

But Ejiofor is the casting coup here, an actor who buys in and makes us join him as he utters even the most exhausted lines in horror — “Look, I know this sounds crazy.” Because it is. Until it starts to make sense, almost in spite of all the over-explaining that dominates the closing scenes.

Rating: R, violence, profanity

Cast: Chiwetel Ejiofor, Renate Reinsve and Mark Duplass.

Credits: Directed by Kane Parsons, scripted by Will Soodik, based on the Kane Parsons video series. An A24 release.

Running time: 1:50