It's the coming-of-age of a gum-chewing gumshoe, from geek to sleek, in the 'meanhalls' of the school that never sleeps. And as such, it's one hilarious genre-spoof that actually works on all levels, the kind that when you're not laughing out right you're grinning from ear to ear. I'd even say it drives a stake thru Twi'blight, especially in regards to the hyper-true-love-of-the-super-mature-movie-teens.
I loved the 'school as prison' backdrop- Shawshank meets Hamlet 2 sort of thing, but neither over-the-top nor under-fed. The bad guys are neither psychotic nor one-dimensional while the good guys (and gal), well, they're not angels and this, again, is pitch-perfect and so refreshing compared to the usual Hollywood polarization.. and kudos on the editing, the dialogue, the pace - everything really.
One questionable casting choice however is Mischa Barton. I can't seem to come up with a better alternative and she is OK but nothing more -as opposed to the rest of the cast. She seems to have some kind of acting-facial-paralysis, very noticeable in her last scene, and for her sake, I hope she learns to transcend this botox-haze she shares with Kirsten Dunst among others. But this is truly a minor (possible) blemish in an otherwise awesome little movie where the whodunnit is somewhat gratuitous but then, you wouldn't want it any other way.