It's not your typical "art house" film about gay cowboys eating pudding. It's not the type of film likely to win any awards. It is, however, brutal, daring and utterly unpedictable - three qualities quite rare in movies these days.

A barely-recognizable Nick Cannon is one of four unaware "guinea pigs," locked in a plain white room after responding to a classified ad for a case study. They fear that the study's effects might give them nausea or diarrhea; oh God, they don't know the half of it.

Blood, guns, gas and psychological warfare are thrown around the room like "Community Chest" cards on a Monopoly board. Trivia questions are asked that even Ken Jennings couldn't possibly answer - that's the point; these guys are screwed. They're told that only one will leave the room alive, and we wonder whether the string-pullers will even be that generous.

The audience's advantage over the "contestants" comes in the form of Peter Stormare and Chloe Sevigny, who overlook the events from behind one-way glass, studying their responses for the government. Cold, icy and mysterious, it's the best performance I've seen by either in years.

Ditto for Timothy Hutton, a hit-or-miss actor who hits hard here. He should do this kind of stuff more often. His ex-con Crawford, locked in a simple room with Cannon's pierced homeless recluse Paul, Clea DuVall's polite Kerry and Shea Whigham's twisted Tony, make for more fireworks than a Michael Bay flick with fifty times its budget.

Director Jonathan Liebesman pulls off a rare feat: Setting an entire film predominantly in one room. All focus is on the eyes, actions, and betrayals of these characters - and the finale comes out of left field, in the best way possible.

It's "Cube" with better actors. "Reservoir Dogs" without the hipness. "Lifeboat" with a modern spin on war-time paranoia.

During one pivotal moment, one of the "Killing Room" guinea pigs claws himself to a small grate, where a glimpse of blue sky offers the promise of something better. Having sat through a few dissapointing films already here at Sundance, I'm grateful that this film has given me a peek at some blue sky.