This enthralling documentary is not just for fans of the thrashing kings of Heavy Metal. This three-year-long study shows a completely different side to the media-projected culture of the band. Maybe they have just grown up, but twenty years after they first began jamming together, Metallica is not what you think they are. Here they battle rehab, themselves and each other, work like demons, and undergo protracted and intrusive therapy to keep their music on track.

It shows the sensitive side of gravel-voiced, devil-may-care front man James. Feisty drummer, and anti-Napster crusader, Lars desperately fights to keep the band together. And mild-mannered Kirk, good-naturedly weathers the continual clash between James and Lars. Most of all, it displays the hard work that constantly pushes the creative boundaries for one album.