British realism on the big screen can be hard to handle: crusty, claustrophobic little pictures full of gray skies and pasty complexions. But Andrea Arnold’s tough, clear-eyed coming-of-age tale Fish Tank adds some juice to the genre. The writer-director takes a plot worthy of a Lifetime TV movie—think Mother, May I Sleep With Your Boyfriend?—and gives it a kitchen-sink makeover, only without the oppressive drabness and didacticism. The film tells the story of Mia, a 15-year-old wannabe breakdancer (impressive non-pro Katie Jarvis) who lives in an English housing project. Mia starts to peek out from her seething haze of adolescent resentment when her mom brings home a handsome new lover named Connor (Michael Fassbender).

What happens between Mia and Connor is hardly surprising; we sense from the moment he appears that this frequently shirtless, affably teasing bloke could be trouble for a teenage girl desperate for connection. But Arnold toys ever so slightly with our expectations, making Connor both an appealing father figure and a shifty, unreadable male presence in an all-female household (aside from the boozy mother, there’s potty-mouthed kid sister). The filmmaker navigates her protagonist’s story with uncommon empathy—her camera sticks by Mia’s side in breathless tracking shots and purposeful close-ups that capture tiny flickers of fragility in a character whom we first see head-butting a rival.

If Fish Tank feels more fluid, more passionate than other recent English films about the wretched working classes, it’s because Arnold dares to inject her stark material with a welcome bit of lyricism. It doesn’t always work—there’s some clumsy symbolism involving a tied-up horse—but it gives the film a sweep that builds toward a finale of startling power and optimism.

Just before that, the director stages one sublime scene—a deeply odd and wrenching moment of familial reconciliation involving hiphop dance that’s unlike anything I’ve ever seen, and worth the price of admission alone.