While Heavy Metal is often accused of being static and conservative, in truth it is a radical form that regularly re-invents itself, and one which attracts generation after generation of musicians willing to learn from the past, but hungry to evolve the future. This film is a study and review of this new dawn in rock music, and with the aid of those who were there at the time, presents both the story of this fascinating musical journey and reassess the sounds, the bands, the impact and the legacy of Thrash.