Chiwetel Ejiofor as Clark in Backrooms. —A24Warning: This post contains spoilers for Backrooms, now in theaters.When failed architect and struggling furniture store owner Clark (Chiwetel Ejiofor) discovers a mysterious portal in the basement of his strip mall warehouse that leads to a sprawling, maze-like dimension of drab, yellow-wallpapered rooms, he becomes obsessed with exploring the nightmarish realm. Unfortunately, he's very much not alone in this liminal labyrinth.Backrooms, directed and co-written by 20-year-old YouTuber-turned-filmmaker Kane Parsons, follows Clark as he drags his assistant manager Kat (Lukita Maxwell), her boyfriend Bobby (Finn Bennett), and, eventually, his therapist, Dr. Mary Kline (Renate Reinsve), down the rabbit hole of this terrifying alternate reality with him. It's a slow-burn horror that relies on the unsettling nature of that uncanny limbo to build atmospheric dread before ratcheting up to true cosmic horror. It also has years of internet lore backing up its premise.Where did the "Backrooms" come from?Clark (Chiwetel Ejiofor) enters an otherworldly dimension in Backrooms. —A24Born from an anonymous 4chan creepypasta post, the concept of the "Backrooms" has evolved from a singular image to a YouTube phenomenon to a buzzy summer horror release. The original photo, which was shared on 4chan in 2019 and later identified as a 2002 snapshot taken at a former Wisconsin furniture store, was accompanied by a request for others to share "disquieting images that just feel 'off.'" Another user then replied to the post with a caption that has come to define the Backrooms mythos: "If you're not careful and you noclip [or glitch] 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. God save you if you hear something wandering around nearby, because it sure as hell has heard you."In 2022, a then-teenage Parsons (known on YouTube as Kane Pixels) debuted "The Backrooms (Found Footage)," the first entry in a series of analog horror shorts that transformed an internet urban legend into a massive viral YouTube sensation. Parsons' Backrooms expanded the creepypasta into an elaborate sci-fi narrative that primarily revolves around Async, a fictional, shadowy research institute that accidentally discovers "The Complex" (i.e., the Backrooms) in the late 1980s and attempts to document it. Following the runaway success of his channel's videos, which have amassed over 190 million views, Parsons was tapped as the youngest director in A24 history to adapt his series into a feature-length film.The movie pulls some lore from Parsons' YouTube universe—including the existence of Async and the disfigured, human-like entities known as Still Lifes that are the result of the Backrooms' failed attempts to replicate people—while also introducing its own characters and plot twists. "I don’t like drowning people in lore and mythology. I think it’s an irresponsible creative choice. It happens a ton online when an independent artist gets to the spotlight," Parsons told Indiewire. "You just get this weird bloat where it becomes very alien to people...who aren’t avid fans of this thing and are approaching it for the first time. They’re suddenly coming into it, and it’s made inherently for YouTube channel dissection."How does the Backrooms movie end?Mary (Renate Reinsve) runs for her life in Backrooms. —A24After Mary happens upon the portal to the Backrooms and decides to go through in search of Clark, he quickly finds her and takes her captive. She wakes to find herself tied to a chair in a room several Backrooms layers down, with Clark and three Still Life-esque entities keeping watch nearby. Clark, who is rapidly unraveling psychologically, insists he belongs in the Backrooms and angrily demands Mary validate his bitter and spiteful tendencies.Then, just as Clark is preparing to untie Mary, the monstrous Lifeform that killed Kat and Bobby and has been haunting the Backrooms ducks through the door. Surprise, it's Captain Clark—a physical manifestation of Clark's rage and aggression that appears as a mutated version of the pirate character we saw Clark dress up as to film a commercial for his Cap'n Clark's Ottoman Empire furniture store earlier in the film—and it proceeds to kill Clark by brutally ripping into his neck with its teeth before pursuing Mary as she attempts to flee.A big chase scene ensues that culminates with Mary beating Captain Clark back with the piece of cement she had pocketed from the driveway of her childhood home that serves as a reminder of her own trauma before escaping down a narrow passageway the entity can't fit into. However, following her escape, she immediately falls into the hands of a group of Async scientists, who take her back to their facility. She's brought to an isolated interrogation room and questioned by an Async employee named Phil (Mark Duplass) who tells her they believe the Backrooms function as a sort of echo chamber for memories, which explains why we see things, places, and people from the real world that appear imperfect or misremembered. Phil also tells her he's not in charge of what happens to her after she's done answering their questions, seemingly implying she may never leave the facility.The camera then pans down through several layers of the Backrooms to show that there's now a distorted, Still Life version of Mary trapped in the supernatural purgatory. According to Parsons, this eerily ambiguous ending was intended to leave the story open to continuing in future installments. "[Sequels are] more than an option—it's been the intention since 2022," Parsons told Polygon. "This film is the first part in what I would desire to be several narrative steps, in terms of approaching what I consider to be the true heart of the idea. I just don't think you could get to it in the time you have for a single movie.”