Michael Crichton's Westworld sounded the first cautionary warning about the possibilities of what could happen when a computerised theme park ran out of control. His Jurassic Park updated the concept, with its additional theme of man tampering with nature. Tron further blurred the distinctions between reality and virtual reality within the framework of a computer game out of control. The Lawnmower Man and its hideous sequel explored the potential of virtual reality, as did the nasty, straight- to-video thriller Brainscan. David Cronenberg's upcoming Existenz also taps into a similar theme, albeit from a more intellectual perspective.

But it was the recent and ambitious, high-tech The Matrix that brilliantly blurred the distinction between the real world and a computer generated virtual world with a barrage of the best cinematic special effects seen this year. This new thriller from producer Roland Emmerich (Independence Day, Godzilla, etc) and colleague Josef Rusnak, who worked as second-unit director on Godzilla, also explores a similar theme. However, The Thirteenth Floor is a high concept idea given a low brow execution, and it will leave most audiences feeling even more confused than The Matrix. At least The Matrix was sufficiently intriguing and dazzling that it drew many back for a second viewing to puzzle out its intricacies. The Thirteenth Floor is unlikely to have the same effect, as once is definitely enough for this disappointing blend of sci-fi and murder mystery.

Computer genius and soft-ware developer Hannon Fuller (Armin Mueller-Stahl) has developed a virtual reality program that enables him to recreate his own imaginary world. He has recreated his own vision of Los Angeles, circa 1937, which he visits at regular intervals through this new technology. But then something goes wrong and subjects from his virtual reality world become able to interact with his real world, with devastating results.

When Fuller is brutally murdered, his collaborator Douglas Hall (Craig Bierko, from The Long Kiss Goodnight, etc) becomes the chief suspect. His attempts to understand what has gone wrong lead him and his technical programmer Whitney (Vincent D'Onofrio) into a world of danger, murder and technological mayhem. It also leads him to the beautiful but elusive Jane (Gretchen Mol, from Rounders, etc). But Hall soon discovers that Fuller's artificial world may not be the only one, and that other people, with more sinister agendas, are also able to move between worlds, manipulating events to their own perverse design.

Eventually, this complex film raises a few questions about technology out of control, and even forces us to question what is real and what is not. Ultimately though, the plot has a number of holes that can't be disguised by technology or whiz bang effects, and director Rusnak fails to create a genuinely unnerving atmosphere. Even the special effects here are rather routine, given recent achievements in sophisticated computer generated imagery. However, the recreation of Los Angeles of yesteryear is quite spectacularly done, and Wedigo von Schultzendorff's muted, washed-out cinematography is quite atmospheric.

The performances throughout are rather bland. Mol looks as though she is sleepwalking through her dual role, while D'Onofrio does his usual angry young man thing with a frightening intensity and flair. Even they seem as unconvinced by all this nonsense as the audience!