This 2005 music documentary, follows anthropologist Sam Dunn as he explores the enduring subculture of heavy metal. Traveling from the UK to the USA, from Germany to Norway, Dunn tries to find out why heavy metal music has been so stereotyped and dismissed, and yet loved so passionately by its millions of fans. Featured bands include Slipknot and Black Sabbath, as well as leading singers such as Bruce Dickinson and Rob Zombie.