After getting out of jail, Sherry Swanson (Maggie Gyllenhaal) f*cks the first man she encounters outside of her parole officer. It's day two at the women's halfway house that she's staying in when Andy, the program supervisor, appears. The exchange goes something like this: Hi. Want some coffee? Cut to: Sherry and Andy having sex in the basement of the house.

This early scene is an apt, if disheartening, metaphor for Sherry's interactions with men throughout this Sundance Lab-born film by writer/director Laurie Collyer. As Sherry, a recovering dope addict, Maggie Gyllenhaal adopts a slouchy prowl, transforming her rangy body into a sex-charged weapon. She's trying hard to stay clean, and to win back the trust of her young daughter who's in the care of her brother, Bobby (the jovial letch from Me and You and Everyone We Know in a wonderfully ordinary performance), and his wife. But, with only a few paltry possessions, no income, and a history of drug use, the odds are against her.

What's more, her past is composed almost exclusively of toxic relationships with men, which form the basis of an unsavory template for how to achieve personal advancement. As a teenager, Sherry stripped to support her heroin habit, and it's also apparent that her father molested her as a child — in the film's present day, they behave together almost like a couple, kissing on the lips and holding hands. When Sherry breaks down because she's losing her daughter's trust, her father fondles her breasts as he comforts her. Even her interactions with women are fraught and charged: a chubby Hispanic woman at the halfway house wants to know why she "thinks she's so special," and the seemingly frivolous girl talk Sherry exchanges with Bobby's wife in one scene carries a bitter undercurrent of competitiveness — a makeover offer sounds like a challenge to a duel.

Certainly the film does have flaws: many of the scenes with Sherry teaching children at a Catholic daycamp ring false, her interactions with her daughter are at times overly saccharine, and Giancarlo Esposito's performance as the parole officer is bafflingly uneven after he gets off to a rousing, overacting start. Yet Gyllenhaal's performance makes these quibbles minor. I often feel inclined to underestimate her skill, viewing roles as tailor-made for her rather than as incredible feats of transformation. But, if it wasn't already clear, Sherrybaby affirms that behind that impish grin is an incredibly talented actress. All bra-less breasts, lanky legs, cheap heels, and purple eyeliner, Gyllenhaal portrays a woman at loose ends, strand by strand, saving Sherry from the cliché fate of a down-and-out single mom. Although her redemption must play by the rules of the movie's game (i.e. she can only be saved by a man), Sherry's salvation comes not because she's a lover, or a whore, but because she's a fighter.