A music documentary about Metallica's making of their album 'St. Anger' and the difficulties they had to go through in the process. Joe Berlinger shot over 1200 hours and followed one of the most successful heavy-metal band in history around night and day for over a year to create this documentary. It tells the trials and tribulations of the group as they cut their first album in six years. The members of the band submitted to two years of intensive group therapy to work through conflicts in their 20-year working relationship.

The story of the longest surviving and certainly the loudest genre of rock, heavy metal. With no sign of disappearing, metal has been the most controversial and misunderstood of all rock genres. With Black Sabbath as the undisputed Godfathers, we follow their highs and lows, and, along the journey, meet Deep Purple, Judas Priest, Iron Maiden and Metallica.