This movie is slightly fucked up. That’s the only way I can think of describing it.
It’s centered around these two high school boys that are stereotypical fuck ups and slackers, except one has a long-term crush on a cute redheaded girl that he must’ve been friends with way back in elementary school or something. These days, she wants nothing to do with him, and prefers the company of preppy, jock douche bags.
The boys decide to cut school and hang out at an abandoned mental hospital and drink some beers. They get buzzed and run around breaking things for no other reason than they can. At least, until they find the dog. And the dog chases them into a crawlspace that feeds into an otherwise blocked off section of the hospital. Here they find a door that’s rusted shut. They pry it open hoping it will lead them back outside. Instead they find a naked girl strapped to a gurney under a large piece of plastic. Naturally, they assume she’s dead. And then she moves.

Sick, twisted shit and depravity ensue. To share details would spoil the fun.
Verdict: See it. If you’re not too squeamish, this is worth seeing at least once.