Looking for the title of a movie, not Reservoir Dogs, where a group of people are in a warehouse and trying to solve a mystery of some sort.

It's not one of the Saw movies, either. I think it's similar to Cube, Circle and Open Grave in that everybody wakes up in the warehouse as opposed to escaping there like in Reservoir Dogs. Everybody thinks everybody else is the reason they're all there, so nobody trusts anybody.

Please help!

edit: I was thinking of Unknown.