Douglass Hall is an employee of Intergraph Computer Company, a corporation that does AI development. Their latest project is an enormous virtual-reality machine that can take people to computer-generated places and meet realistic people inside the artificial world.

One day, however, Douglass' boss, Fuller, is murdered. There is much evidence pointing to Hall -- a shirt stained with Fuller's blood is even found in his apartment, but Hall has no recollection of what he did the night of the murder. Fuller's daughter, Jane, soon arrives to take control of the company and shut down the virtual reality machine. In the meantime, Douglass, with the help of his co-worker, Whitney, enters the virtual-reality program to find a message left for him by Fuller and attempt to find out more about the murder.

"The Thirteenth Floor" is a decent mystery movie with some good action. However, it takes a long time for the action to get started. Also, besides the addition of the virutal reality program and a bizarre plot twist, this movie is just another standard murder mystery.