I was a little disappointed when I left this film, but not because of the overall result. I was disappointed because of the wonderful way in which the story was laid out and unfolded itself in the beginning, then seemed to fall away during its 2nd act. The reverse theme of bad kids turning good was fascinating, and the paranoid performance by Nick Stahl was worth watching and intrigued me. But then, as soon as Stahl was converted, the film started to fall apart. For one Stahl was the only character I found to be truly worth watching. Marsden and Holmes were just two pretty faces noticeably void of much talent; I never believed the two as a couple, and I never found any reason to invest myself in hoping for their well-being other the fact they were the lesser of two evils. But most noticeably, I grew disinterested because of the change in aim by the makers. The first half of the film, which by itself I would have given an 8 or 9 out of 10, was more of a grown-up horror movie, where the situation and plot rather than actions dictated the fear of the audience. But after Stahl disappears to the dark side, the film changed into a teen slasher film almost, where blood, violence and screaming is used in a vain attempt to induce fright. This 2nd half was worth a 4 or 5 out of 10. The length did not bother me as much as others (I've seen plenty of effective movies that were under 90 minutes). What bothered me more was the lack of development in some key plot points. I think the entire conspiracy plot behind the conversion of the teens needed to be fleshed out much more, characters needed to be drawn more distinctly, and so on. So I balance out the two halves and come up with a 6 out of 10. Worth renting, but could have been something special.