Mia strides purposefully around her Essex housing estate and fairly bleak environs. The problem is that she’s desperately short on purpose. In the first few minutes of Fish Tank, the film’s heroine stalks about in a grey hooded track suit over a black sleeveless t-shirt, something of a second skin. She summons a neighbor girl by throwing rocks her window and then leaves an expletive of a calling card with the girl’s father. She confronts a group of hostile girls and head-butts one of them with force enough to draw blood. Finally, walking along a motorway, she notices a woebegone old white horse tethered in a vacant-seeming lot, which she tries to free by pounding a rock on its lock and chain. Those last two acts are alike in their futility and defiance. They tell us more than a little about Mia, who will clearly push back when provoked and longs to feel for or believe in something, much as the unlikely objects of her affection tend to disappoint her. Mia’s main source of disappointment...