Shadowplay (2007)

Shadowplay is a psychological thriller about three individuals who wake up imprisoned in a metal cell with no memory of who they are or how they got there. As fear and confusion threaten to tear this trio apart they are presented with a clue: a metal box, immovably heavy and as solid as the walls that imprison them.It is clear they must work together to solve the boxs riddle, but as the trio struggles to open it they begin to remember things about their own pasts, things that make it difficult - and dangerous - for them to trust each other.Nor are they certain that opening the box is even such a good idea! [imdb]