It's one of those movies where you need to turn off your brain before the credits start. Much of it is contrived and there are plot holes that you can drive the villains truck through. If you spend any time at all thinking about what's happening you'll laugh at it, but if you manage to just watch without trying to analyze things it's got a lot of suspense and beats the hell out of most of the slasher/gore flicks that pass as a thriller these days. I give it a thumbs up, but only because the current crop of movies has been so bad. Training Day has been the only decent film recently and even that one falls apart in the last half hour.