I went into A24's $400 million horror hit 'Backrooms' knowing nothing. That might be the best way to watch it on HBO Max

(Image credit: A24) A24's highest-grossing film to date, the surreal horror flick "Backrooms," is finally on HBO Max. One of the biggest hits of the year so far, it grossed nearly $400 million and — along with "Obsession" and "The Odyssey" — turned this summer into the busiest season theaters have seen since the pandemic.If you’ve ever fallen down the internet’s weirdest rabbit holes, chances are you’ve encountered the backrooms, a concept that first began as a photo posted online of an empty department store under renovation. The unsettling liminal expanse hooked itself into the collective consciousness of the internet, spawning countless videos, games, and theories about what might be lurking just out of sight in those yellowed halls.After the trainwreck that was 2018's "Slender Man," I didn't have high hopes for another bit of internet lore getting the big-screen treatment. But I was happily surprised! For his first movie, director Kane Parsons' artistry and vision are incredibly impressive. The composition alone had me seeing "Backrooms" twice in theaters. Now that it's one of a ton of new movies on HBO Max in September, I'm excited for even more folks to check out this delightfully bizarre horror movie. Also, there's no lore you need to know to enjoy it (trust me, I went in knowing zilch).If the idea of getting trapped in an endless maze of fluorescent-lit rooms already has your skin crawling, here's everything you need to know about “Backrooms” now that it's streaming on HBO Max.What is 'Backrooms' about?Ain't that the question. How do you describe a dream? Give that dream a bunch of unnervingly yellow hallways, a sense that you're constantly being watched, and one giant pirate, and you've got "Backrooms." Backrooms | Official Trailer HD | A24 - YouTube Watch On In this surreal, slow-burn nightmare, Chiwetel Ejiofor stars as Clark, a freshly divorced furniture store owner struggling to get his business out of the red. One night, he uncovers a hidden doorway in the store's basement that leads to a seemingly endless network of interconnected rooms that defy reason and physics. Mapping out its dimensions turns into an obsession, and he soon realizes he's not the only lost soul wandering its halls.Worried about her patient, Clark's therapist, Mary (Renate Reinsve), does a wellness check and wades into the same terrifying hidden world. Its twisted corridors are now home to something sinister, and worse, Clark, his bitterness amplified by whatever corrupted power this place holds, is playing house with it as his sanity unravels.Sign up to the weekly Tom's Streaming Guide to stay in the loop with the latest releases and top recommendations across your favorite streaming services. We’ve got you covered with a complete guide on what’s worth watching.Why you should stream 'Backrooms' on HBO Max now (Image credit: A24)I'll never miss an excuse to yap about weird movies, and "Backrooms" is one of the most commercially successful in a long time. Its brand of horror definitely leans more atmospheric, milking scares from drawn-out chase sequences and the sheer weirdness on display at every turn.Parsons’ debut taps into a dark and unsettling feeling from the very start, and that sinister tone carries throughout the film. Clark and Mary's wanderings feel more like prey being stalked, the liminal labyrinth transformed into a threat that makes even less sense the more you see of it.Though you don't need to know any of the Backrooms lore to follow the plot, I will say it doesn't hold your hand as you enter this bizarre world for the first time. How the film chooses to answer — and deliberately avoid answering — leaves viewers a lot of room to fill in the blanks themselves. That's not going to be to everyone's taste, but if you’re willing to let the story take you to the horrifying and cerebral lengths it wants to go, I promise you're in for a treat.Watch "Backrooms" on HBO Max right now Follow Tom's Guide on Google News and add us as a preferred source to get our up-to-date news, analysis, and reviews in your feeds. Subscribe to Tom's Guide on YouTube and follow us on TikTok. Finally, you can visit our dedicated Tom's Guide Savings Squad hub for expert help on getting the best products for less. More from Tom's Guide7 top new movies to stream this week on Netflix, Prime Video, HBO Max and more — including ‘Backrooms, 'Toy Story 5' and an action-thriller film ‘John Wick’ fans will love (Sept. 22-28)How to get HBO Max for free — here are 4 waysThe best streaming services in 2026 Alyse Stanley is a news editor at Tom’s Guide, overseeing weekend coverage and writing about the latest in tech, gaming, and entertainment. Before Tom’s Guide, Alyse worked as an editor for the Washington Post’s sunsetted video game section, Launcher. She previously led Gizmodo’s weekend news desk and has written game reviews and features for outlets like Polygon, Unwinnable, and Rock, Paper, Shotgun. She’s a big fan of horror movies, cartoons, and roller skating. She's also a puzzle fan and can often be found contributing to the NYT Connections coverage on Tom's Guide