The film stars Milo Cawthorne as Brodie, a human encyclopaedia of all things metal that is forced to move to a small New Zealand town to live with his religious aunt and uncle after his mom is arrested for performing fellatio on a mall Santa during a meth binge. A natural born outcast, he's too awkward and inexperienced to know the girl he likes also likes him, takes daily beatings from his jock cousin (who also happens to be her boyfriend), and hangs with guys who play Dungeons and Dragons during their lunch break.
But when Brodie meets fellow metalhead Zakk (James Blake), everything changes. The two stumble upon a long-lost batch of sheet music said to give power and fortune to whoever plays its song. After giving it a Black Sabbath-y treatment during band practice, they accidentally end up transforming their fellow townspeople into dead-eyed, blood-hungry beasts, and start a chain of events to bring the God of Demons to the mortal world.
What follows is an action adventure with enough blood and guts to rival national treasure Dead Alive and Sam Raimi's Evil Dead, while keeping things equally light and silly with some seriously immature comedy (double-sided dildos are a weapon of choice in this film).
Grotesque battle scenes aside, few films capture the uncomfortable reality of being a metalhead in a small town quite like this one; it may be worth seeing just to watch a long-haired hessian in corpse paint eat a strawberry ice cream cone alone.