In a building in Amsterdam, an elevator inexplicably begins to function alone. After a lightning storm causes a power failure and traps four people in the elevator, the elevator will not open after even after a subsequent power restore and the passengers almost suffocate. Soon, subsequent malfunctions prove fatal as an elderly blind man falls to his death when the elevator doors open to an empty shaft, the building night watchman is decapitated by the elevator doors, and a janitor is snared in the shaft in which his body drops through the elevator ceiling hatch.
Felix Adelaar (Huub Stapel), a technician from the elevator company Deta Liften, begins to examine the electrical system in an attempt to find any anomalies. During the course of several inspections, he meets Mieke de Boer (Willeke van Ammelrooy), a journalist for De Nieuwe Revu, a local tabloid that Felix remarks he often finds in his friends' cat litter. When inspections reveal no apparent problems with the electrical system, Felix becomes obsessed with the continuing malfunctions of the elevator, not even taking time with his wife Saskia (Josine van Dalsum) and their friends. While Saskia begins to have suspicions, he continues his investigation by examining the manuals with wiring diagrams. When Felix pays yet another visit to the building, he notices a van parked outside from Rising Sun, a manufacturer of microprocessors for automation and a secret supplier of experimental microprocessors to Deta Liften. Felix and Mieke, after collecting newspaper clippings about Rising Sun, try to meet with the company's CEO, who acts nervous and answers abruptly.
Saskia finds out about his recent activity and angrily confronts him at dinner, but their argument is interrupted by a call from Mieke who invites Felix to meet up with her former university professor who specializes in electronics. The professor explains microprocessors' sensitivity to external factors, such as electric fields, magnetic fields, and radioactivity, which undermine the proper functionality. He tells about a computer built years ago which suddenly begun to self-program and went out of control.
The next morning, Felix is summoned to the elevator factory by his boss, who angrily suspends him for his unauthorized visit to Rising Sun. That evening, the owners of Deta Liften and Rising Sun have a meeting inside a car, and reveal that the elevator's controller, made out of organic material, is going rogue by killing people in which makes them nervous.
Soon enough, Felix's wife leaves with their children and, feeling that he doesn't have anything left in his life, decides to solve the elevator conspiracy. Gaining inside the building during the night, the elevator reveals its sentient mind as it operates properly until he tries to access the shaft at which point it crushes the chair he was using. After going to the top floor to find the metal enclosure containing the microprocessor empty, he enters the elevator shaft by climbing onto the carriage and discovers a pulsating box with sticky goo around a silicon chip functioning as a heart. As he attacks the box with his screwdriver, the microprocessor starts the elevator at high speed and attacks Felix with its counterweight. He falls, but manages to catch onto a ledge below a set of elevator doors. As the elevator car hovers above him and the cables begin to fray one by one, Felix furiously scrambles to open the doors from the floor below, but Mieke reaches in and pulls him out just as the final cable breaks and the car falls below.
As Rising Sun's CEO arrives to see that his experiment failed, he pulls out a gun and fires into the biocomputer to seemingly kill it. The computer then shoots one of the broken cables out to drag him inside the shaft and hangs him. As a shaken Felix and Mieke walk down the stairs and the credits roll, the screen soon turns green A shaken Felix and Mieke decide to take the stairs. As they walk downstairs and the credits roll, the screen turns green and the elevator's heartbeat continues.
On aggregator website Rotten Tomatoes, it has an audience score of 38% based on 665 reviews.