Bound to the mortal world by a powerful spell no demon could hope to break, Cain Pseudomantis must obey his human master's every command or face harsh punishment. Then everything changes. While on a mission in a seedy section of 1980s Los Angeles, Cain buys an electric guitar and discovers an unusual talent that catapults him to hair metal stardom. With three superpowered human band mates and his beautiful girlfriend Michelle by his side, his life starts to look a lot better...but when Cain and his friends try to unmask a mysterious killer, they discover a deadly secret.