"The Killing Floor" is a horror movie that turns the tables on the main character. The movie stars Marc Blucas as a man named David Lamont who works with horror novelists and doesn't seem to have time to focus on life outside of his career. When he moves into a penthouse, he finds himself in the middle of a story his horror novelists might write.
The movie opens with overworked literary agent Lamont on the phone negotiating as he is shown the new building where he intends to live. His assistant Rebecca points out that he forgot to make a job recommendation for a friend, another sign that he is too busy. Lamont also turns down an aspiring author in a rude manner. He also tells Rebecca that he will read her script, though he never does and has no intentions of doing so. Later, he bumps into his new neighbor Audrey while jogging and invites her to a party with coworkers and writers from his agency.
After the party, odd things begin happening to Lamont. When he returns home, he is struck on the side by a lone car that drives down his street. While shaken up, he realizes that he is not physically hurt. Once he settles down and falls asleep, he is awoken by a policeman who tells him that a man claims he rightfully owns Lamont's penthouse because it was his father's. The policeman gives him a business card in case there are problems. One night after work, he finds an envelope filled with photos of murders that look to have happened in his building. Lamont is startled when he hears noise, but it's Audrey waiting for him. She suggests that his house has a dangerous past.
Things get worse when he begins to investigate his house. He gets trapped in the building elevator and finds a videotape chronicling a series of murders that look to have occurred in his penthouse. He later gets a phone call from someone who can see him. Scared, he goes to stay with Audrey. He begins getting in routine contact with the police officer who came to his home, letting him know about all of the things he is finding.
Lamont finds out that Rebecca has been spying on him and asks her if she has seen anyone mysterious going in and out of his building. She says she hasn't but remembers the policeman in the novel Lamont rejected having the same name as the policeman he has been contacting. Lamont realizes the policeman must be the rejected author and thinks he is the one that has been terrorizing him. The two get into a fight and Lamont accidentally kills him. He also discovers Audrey's body and thinks the fake officer must have killed her. He thinks he will be blamed for the deaths and Rebecca urges him to cover it up. After he disposes of the bodies, he returns home and opens Rebecca's script. The story details what happened to him and reveals that Rebecca was behind many of the odd occurrences, including the policeman who was an actor she hired.