An upcoming A24 horror film will imagine the fictional world of Backrooms, a niche digital-era urban legend that’s gone mainstream.

Backrooms, starring Oscar-nominated 12 Years a Slave actor Chiwetel Ejiofor and Sentimental Value’s Renate Reinsve, is inspired by the imagery and storytelling surrounding “creepypasta” — an internet myth that went viral after it was published to the anonymous forum website 4chan in 2019.

Backrooms is a fictional liminal space containing an expanse of eerie, empty rooms that hide hostile creatures (think of the never-ending hallways in Apple’s acclaimed series Severance or the sinister setting in the 1997 horror film Cube).

In Backrooms, the liminal space is presented as a yellow, empty, never-ending office found behind the walls of an industrial retail outlet. It follows Ejiofor’s character as he stumbles upon the expanse of the Backrooms and makes it his mission to explore its hallways. His therapist, played by Sentimental Value star Renate Reinsve, ventures in after him, and the results appear to be terrifying.

The concept of Backrooms first originated when a 4chan user shared a photograph of a large, sterile carpeted room with fluorescent lights on a paranormal-themed board, asking users to “post disquieting images that just feel ‘off.’”

In 2019, a user replied to the post, giving the image genre the name of “Backrooms” and offering up a fictional theory to accompany it.

The post read: “If you’re not careful and you noclip out of reality in the wrong areas, you’ll end up in the Backrooms, where it’s nothing but the stink of old moist carpet, the madness of mono-yellow, the endless background noise of fluorescent lights at maximum hum-buzz, and approximately six hundred million square miles of randomly segmented empty rooms to be trapped in.”

It continued: “God save you if you hear something wandering around nearby, because it sure as hell has heard you.”

In response, other users started to imagine their own stories about Backrooms on Subreddits such as r/creepypasta and later r/backrooms.

The liminal space community has since expanded on the concept of the Backrooms, introducing concepts such as “levels,” which are different layers of the Backrooms that are interconnected, and “entities,” which are creatures that inhabit the spaces.

In early 2022, American YouTuber Kane Parsons, AKA Kane Pixels, posted a series of Backrooms short films on YouTube, which popularized the fandom and its storytelling further.

At 20 years old, Parsons is the director behind the A24 film, with Ash vs. Evil Dead writer Will Soodik penning the screenplay.

The first trailer has premiered with the tagline “Everything Must Go,” as the audience hears, “Sometimes I’m scared I’ll get lost,” and “It’s like a maze — it just goes on and on.”

Creep actor Mark Duplass, A Knight of the Seven Kingdoms star Finn Bennett and Shrinking’s Lukita Maxwell also appear in Backrooms.

Backrooms is released in theaters May 29.