Five men wake up locked in a warehouse with amnesia: sounds like the premise for the next ‘Saw’ movie, but this thriller is a less grisly affair. With no memory of either their identity or recent events, the men quickly establish that they’re in a kidnap situation. One of them (Joe Pantoliano) is tied to a chair, and another (Jeremy Sisto) has been shot. Gas appears to have leaked during a struggle. But which are captors and which are victims? Suspicions abound, but the men must work together to escape. Meanwhile, one of their wives (Bridget Moynahan) waits anxiously for news from the police. The identity confusion gives plenty of opportunity for double-crossing, and the mystery is initially engaging. There’s a terrific ensemble cast, too, including Jim Caviezel, Barry Pepper, Peter Stormare and Greg Kinnear. But once the expositionary flashbacks start to kick in, ‘Unknown’ becomes less involving, robbing the warehouse scenes of tension and the characters of depth. The twists are delivered with a heavy hand, resulting in a decidedly average psychological thriller.