What actually happens
A breaker box and a glowing crack
The movie opens in 1990, when Naren Warne, a researcher at the Async Research Institute, is separated from his group and lost in the Backrooms, a maze of dull yellow rooms with fluorescent lights, long corridors and warped furniture. He is chased and killed by something unseen, and Async scientists watch the recovered footage. Some time after that, Clark, an architect who failed and now runs a furniture store that is losing money, is trying to cope with his drinking and his troubled marriage. He sees a therapist, Mary Kline, who is dealing with her own trauma after her childhood home was torn down and her mother was committed to an institution. Clark films a commercial in a pirate costume with help from Kat, his assistant manager, and her boyfriend Bobby. While he checks the breaker box, he finds a glowing slit in a wall, falls through it, and finds Naren's belongings. Something chases him, and he gets back to the store. A scientist named Phil watches it all on a surveillance camera.
Reading this instead of watching it is the correct decision. Scaredy Cat makes that decision automatic, for free.
Bobby gets dragged off at the slope
Once he has explored for several days, Clark tells Mary about the Backrooms, and she doesn't believe him. He needs proof, so he takes Kat and Bobby in to film. In a steeply sloped corridor, an unseen entity ambushes Bobby and drags him away, and he does not survive. Clark and Kat chase after him and get separated in an unexplored area. Clark carries the camera and meets two humanoid entities, which chase him until he hits a dead end. Kat can see him through a wall, though he can't see her. Clark puts down the camera, and something unseen picks it up while Kat screams for him to look behind him.
A cryptic message on an answering machine
Some time later Mary gets a cryptic answering machine message from Clark, saying he is staying in the Backrooms and won't be back. Phil, at home watching television with his family, sees Clark in the furniture store's commercial. Worried about Clark, Mary goes to the store and enters the Backrooms herself. She finds a crude, cryptic mural. Clark arrives, apparently unhinged, and when something approaches he tells Mary to stay calm, then chokes her until she passes out.
Dinner with three simulacra and a pirate
Mary wakes tied to a chair in a room that looks like a dining room, with Clark and three barely moving human figures. Clark shows her they are made of some edible white material. This is the scene to brace for, and it comes near the end: he opens a refrigerator and shows her Kat's severed head. He demands that Mary continue their therapy sessions, and she tells him instead that his wife left because he never took responsibility for his failures. He starts to untie her, but a huge, distorted copy of himself in the pirate costume arrives. Clark tries to calm it, and it kills him, then chases Mary through shifting rooms to a flawed copy of the furniture store. Cornered, she smashes it in the face with a hunk of concrete taken from the house she grew up in. The fight sets off an Async gas trap, and researchers in hazmat suits subdue the monster and take Mary to their facility.
An interrogation room with a spare Mary in it
After she recovers, Mary is questioned by Phil in an interrogation room. He explains that Async used to build medical scanners until it found the Backrooms, which are now its main research. When he asks how she found the place, she gives Clark's own description: a flawed, misremembered copy of reality. She asks if Async will let her go, and Phil says that isn't his decision. Back in the Backrooms, the spaces shift to reflect what Clark and Mary went through, ending in a rough copy of the interrogation room where a deformed version of Mary sits still and silent.
The ending, explained
After the fight with the pirate monster, Async researchers in hazmat suits take Mary to their facility. She recovers and is questioned by Phil, who tells her Async used to build medical scanners before it found the Backrooms. She describes them the way Clark did, as a faulty copy of reality, and asks if she can leave. Phil says the decision isn't his. Meanwhile, the Backrooms rearrange themselves around Clark's and Mary's experiences, and the movie ends in a copy of the interrogation room with a deformed version of Mary sitting there silently. Naren, Bobby, Kat and Clark are all dead.
The post-credits ruling
There is no post-credits scene. You can leave when the credits start.
✓ Spoiled safelyDog status: there is no dog, though a seagull dies.
Questions people ask at 1am
Is Backrooms scary?
Yes. Backrooms is a 5 out of 10 with medium dread: slow tension in endless yellow rooms, loud jump scares, and some grisly sights.
How does Backrooms end?
In Backrooms, Mary survives the monster shaped like Clark in his pirate costume and is taken to the Async research facility, where Phil says it isn't up to him whether she can leave. Clark, Kat, Bobby and Naren all die.
Does the dog die in Backrooms?
There is no dog in Backrooms. A seagull dies.
Is there a post-credits scene in Backrooms?
No. Backrooms has no post-credits scene, so you can leave when the credits start.
What are the Backrooms in Backrooms?
In Backrooms, they are a strange extradimensional maze of dull yellow rooms, fluorescent lights and warped furniture. Clark describes them as a faulty, misremembered copy of reality, and the Async Research Institute studies them.
