A pair of misfit heavy metal fans who unintentionally summon a demon. After his mother is institutionalized, misfit Brodie is sent to live with his fundamentalist Christian Uncle Albert and Aunt Mary, whose son David torments him. A heavy metal fan, Brodie forms a band called Deathgasm with his friends Zakk, Dion, and Giles. When the bandmates break into a local house, they discover that one of their idols, reclusive musician Rikki Daggers, lives there. Daggers gives the band magical sheet music, which a cult later murders him to find. Skeptical of the sheet music's power, the band plays it, only to summon a demon. With the help of his crush, Medina, and his bandmates, Brodie must find a way to defeat the demon.