FISH TANK

★★★ out of four stars

Not rated

Where: Lagoon.

The most honored British film of 2010 is Andrea Arnold's "Fish Tank," and rightly so. The Cannes Jury Prize winner is an intimate look at teen alienation and first love in an English tenement.

Mia (Katie Jarvis) is a scrappy 15-year-old living with her young, neglectful single mom and foul-mouthed little sister, a family unit where "I hate you" is a tender emotional exchange. Mom's new boyfriend (Michael Fassbender, unrecognizable as the suave spy from "Inglourious Basterds") looks as if he might be a positive influence. He treats everyone tenderly and encourages Mia to follow her dream of being a dancer. Director Arnold plays their evolving relationship for every ounce of suspense as the hormonal girl and the ruggedly handsome newcomer move from friendship into more treacherous waters.

The characters are guarded, and as we come to understand them scene by scene, they become ever harder to sort into convenient categories of hero and villain. Mia is a delinquent in the making; with love and attention, she softens, but that vulnerability comes at a cost.

The film is a strong addition to the English filmmaking tradition of welfare-class humanist melancholy where the state of the dishes in the kitchen sink tells us all we need to know about the emotional arc of the characters. Arnold gives us reason to hope that once Mia escapes the fish tank of her shabby council flat she will learn to swim in open water, but she provides no guarantees.

COLIN COVERT

PRODIGAL SONS

★★★ 1/2 out of four stars

Not rated

Where: St. Anthony Main.

Leaping from Helena, Mont., to Split, Croatia -- by way of Old Hollywood -- Kimberly Reed's compelling documentary is filled with revelations. Some of these are emotional, as when the filmmaker returns home to Helena after a 20-year absence to find that her friends treat her no differently from when she was a handsome jock named Paul McKerrow. Others are circumstantial, like the bombshell that reveals her adopted brother, Marc, as a blood relative to Hollywood royalty.

At the film's core, however, is the loving but long-combative relationship between Reed and Marc, a connection that ties both to a past that neither recalls with fondness. Seriously brain-damaged in a car accident, Marc suffers from seizures and terrifying mood swings (in one particularly painful scene, he brutally attacks the sexual choices of his sister and their gay brother, Todd), but Reed and her cinematographer, John Keitel, never sensationalize. Maintaining a simple, naturalistic style, they patiently capture the shifting dynamics of a family hanging in without giving out.

A tale of two siblings -- one basking in memories, the other fleeing them -- "Prodigal Sons" grapples with identity through the prism of sibling rivalry. In the end its conclusions have little to do with gender and everything to do with acceptance.

JEANNETTE CATSOULIS, NEW YORK TIMES