Unknown (2006) - Synopsis

In the same vein as The Usual Suspects and Memento, Unknown is a psychological thriller about five men who wake up in a chemical warehouse and realize they don't know who they are or how they got there. But through time they deduct that some of them are hostages and some are kidnappers. The men now must figure out who is who as they've learned the lead kidnapper is on his way and plans to kill the hostages.