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 fails to open 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, and a janitor is seemingly burned alive.
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. When inspections reveal no apparent problems with the electrical system, Felix becomes obsessed with the continuing malfunctions of the elevator; this has a negative impact on his marriage as his wife Saskia (Josine van Dalsum) begins to suspect he is having an affair. 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.
Mieke 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\\\'s boss angrily suspends him for his unauthorized visit to Rising Sun. That evening, the owners of Deta Liften and Rising Sun meet to discuss how to stop the elevator\\\'s computer processor, which is built from organic material, from killing people.
Saskia leaves Felix, taking their children with her. With nothing left to lose, Felix goes to the building to solve the elevator mystery. He discovers that the elevator has a sentient mind when it tries to prevent him from accessing its microprocessor. Instead Felix climbs into the elevator shaft and finds a pulsating box; inside is sticky goo covering a silicon chip—the elevator\\\'s heart. As Felix attacks the box with a wrench, the elevator uses its counterweight to knock him off balance. He manages to land on a ledge just below the elevator doors, and is rescued by Mieke just before the elevator is able to crush him.
As Rising Sun\\\'s CEO arrives to see that his experiment failed, he pulls out a pistol 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 the elevator\\\'s heartbeat continues.
