The opening shot of The Runaways is one of blood dripping and soaking into concrete - menstruation blood from a valley girl blonde experiencing her first period. A jarring, in-your-face welcome, it sets the tone for an angry bio-pic about young girls becoming women in 1970s America, clashing violently and rebelliously against a gritty societal reality.Written and directed by the largely unknown Floria Sigismondi – from a book by former Runaways singer Cherie Currie – this is the purest rock n’ roll flick to hit theatres in a decade, and ranks with the best ever. Detailing the early days of the now legendary Joan Jett and the formation of her breakthrough all-girl band, it heaves and bleeds with angry authenticity, channeling the same raw exploration and excitement shared by the music and its young, inexperienced heroines...