Cant remember name of movie?

There was a movie in theatres I think last year. It's about these people who wake up in a warehouse (that is atleast what it looks like) and don't remember what happened. And they're all being held against their will. But one of them is really the person who is doing it all. And they all have to figure it out. Sorry I know it's vague, but I really want to see this movie. It's basically an R rated thriller I'm assuming.

Cant remember name of movie?opera house

The movie title is "Unknown"

Cant remember name of movie?dream theater opera theater

Unfortunately, you just described several horror movies that came out last year (some direct to DVD) - all of which are variations on SAW.

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maybe its SAW ..or UNKNOWN
Saw
i think your talking about Saw 2..

-Jigsaw locks a few unlucky people in a booby trapped shelter and they must find a way out before they inhale too much of a lethal nerve gas and die. But they must watch out, for the traps Jigsaw has set in the shelter lead to death also.

Thats the only one i can think of.. hope this helps.
SAW II
Is it a Saw movie, Saw3 and they are being tortured, I think thats what you're talking about.
It sounds like several movies. A couple that come to mind are Saw 2 and Mindhunters. Mindhunters is an older movie (2003, maybe?) about FBI profilers, starring Val Kilmer and Christian Slater.