Fifteen-year-old Brit b-girl Mia is a volatile cocktail of emotional vulnerability, emerging sexuality and simmering aggression, a restless, impulsive creature as likely to gently caress a horse as administer a vicious head-butt. As played by Katie Jarvis, she’s also one of the most mesmerizing cinematic characters you’ll ever meet. Director Andrea Arnold’s hand-held camera submerges us in Mia’s turbulent world, which she shares with street toughs, her potty-mouthed younger sister and her promiscuous, neglectful mother. When Mom gets a charming new boyfriend, Mia’s own feelings of attraction lead to unfortunate complications. Michael Fassbender denies viewers an easy reading of the boyfriend character as a simple slimeball, his complex performance nicely complementing the screen-searing Jarvis. It’ll make you squirm, but you’ll be thinking about Fish Tank for days.