With her debut film, [Red Road], Andrea Arnold proved that she was unafraid to shine a light on Britain’s simmering frustrations and the alienation felt by the individual. In [Fish Tank], an unflinching study of a troubled teen, Arnold treads the ground of difficult sensuality and sexuality, with 15-year-old Mia at the center. Mia spends most of her time drinking and nearly squatting in an abandoned apartment when her universe is upended by the arrival of her mother’s new boyfriend. There is an instant attraction between the two that sees Mia testing her newfound power as a sexual creature. Mia’s desperate attempt to make her mark on the world is wrenching, uncomfortable, and utterly believable, and Arnold’s stark depiction of smothering council housing life is a coarse, naturalistic one that makes Mia’s choices all the more unsettling. Non-professional Katie Jarvis makes Mia aggressively realistic and empathetic despite her uniquely British environment. She makes her seem like a fish trapped inside a tank hoping to escape it somehow.