This first-time effort from the director (Vincenzo Natali) and writers, using a cast of unknowns, is remarkably effective despite everything that looks like it could go wrong but doesn't. The limited budget and the fact that they only use one set would make you think it would be pretty cheesy, but this movie will surprise you.

A group of people wakes up in an elaborate maze of nearly identical cubes, some of which contain deadly booby traps. There are quite a few people at first, but the cast is quickly pared down (pun definitely intended) to a few principals: Maurice Dean Wint as Quentin, Nicole de Boer as Leaven, and David Hewlett as Worth. There is no explanation of why they were chosen or who has kidnapped them. All they know is that they have to get out or slowly starve to death.

As the movie wears on, and the traps get worse, the characters discover that each of them has some skill that, working together, will enable them to escape. If it sounds like a Dungeons and Dragons game gone awry, it's probably because the filmmakers used to play. All of the actors are effective, and it is surprising that, even though the sets consist of identical cubes lit in different colors, it never gets boring. The sheer inventiveness of the traps, as well as some gradual but effective character development, makes it worth the ride. The claustrophobic tension builds to a shocking conclusion that I didn't exactly see coming, and I can't ask for much more from a thriller.