Into the Black begins on the eve of the release of Metallica's massive breakthrough with the eponymous LP that became known as "The Black Album." Suddenly, at the dawn of the '90s, Metallica was no longer the biggest thrash metal band in the world--they were the biggest rock band in the world, period.

But with such enormous success came new challenges, as Metallica ran the risk of alienating their original fan base. They were beset by controversy over musical stylistic shifts, supposed concessions to the mainstream, even their choice of haircuts.

During this...