Anarchistic and blazingly human, "Hesher" thrashes onto the scene like the Metallica tunes the title character blasts on his truck radio, first at full volume and then gradually softening to reveal a deeper empathetic propensity. Either way, it remains fiercely protective of, and true to, itself. Having premiered to a warm reception at the 2010 Sundance Film Festival, it is both understandable and perplexing why it has taken well over a year for the film to see an official theatrical release. Profane but honest, at times broadly acerbic and at others close to devastating, the picture may be too much for close-vested mainstream audiences, yet it delves into universal themes involving familial loss, the reverberations of grief, and the struggle to make some kind of impact on the world that should speak loudly to most viewers. The lack of compromise that writer-director Spencer Susser and co-writer David Michod, both making their strong feature debuts, lend to the story is impressive, particularly as they navigate a balancing act of defiant tartness and unexpected emotional compassion. Equipped with a top-to-bottom cast doing standout work, Susser and Michod make a convincing case for how alive and fresh and satiating indie cinema often is these days in comparison to major-studio Hollywood's increasing sway away from good writing and original stories in favor of sequels, remakes, safe formulas, and empty bombast.

It has been two months since his mother was killed in a car accident, and preteen-aged T.J. (Devin Brochu) is still shell-shocked. He functions day to day, going through the motions with school while obsessing over getting the totalled SUV she died in back from the impound lot. Father Paul (Rainn Wilson) is in even worse shape, staying in his pajamas and moping about with no idea how to escape the torturous pall that has settled overtop him. The two of them live with T.J.'s kindly grandmother Madeleine (Piper Laurie), on the verge of senility and unsure about how to help her family. For all intents and purposes, their home life is akin to a funeral. That's why, after T.J. gets into an altercation with the straggly-haired, frequently bare-chested Hesher (Joseph Gordon-Levitt)—he throws a rock through the front window of the under-construction house he's been squatting in—Paul and Madeleine barely notice when the unkempt, enigmatic, twenty-something rebel invites himself to move in. T.J. is at first frightened, then frustrated, by Hesher, who almost goes out of his way getting T.J. into hot water with everyone from school bully Dustin (Brendan Hill) to the local police. Refusing to leave, Hesher and his antisocial tactics prove little by little to be exactly what T.J. and Paul need to shake them free from their lingering anguish. Before things get better, however, they may have to first endure one more of life's blows.

"Hesher" hits a nerve that few movies ever do. It's crass and unsuspecting at the onset by the sheer nature of Hesher himself, but hits surprising beats and journeys to revelatory places as the other characters surrounding him grow into authentic, non-contrived people with the sorts of problems and concerns we all must face. T.J. never once comes off as a script-constructed movie brat, but a child on the edge of adolescence just trying to escape the wraths of bullies and people who don't understand what he's going through. His grandmother, bless her, is sweet to him, but also dotty; when she continues to ask him if he'll take a walk with her, he keeps saying "maybe later," not understanding—even with what has happened to his mom never far from his mind—that one day there won't be a "later." With his dad in a bad spot but trying to get better—he insists that the two of them attend a grief group, a desperate effort to pull them from their funk—and Hesher hoarding in on him and his foibles, T.J. searches for comfort but doesn't know how to find it. When he befriends down-on-her-luck grocery store cashier Nicole (Natalie Portman) after she saves him from an attack by Dustin, he is initially distant with her, then begins to see her as someone who is finally willing to listen to him. The crush on this older girl that forms is innocent and sweet, but when his expectations are not met and he's let down by her, it's the final straw. Like a water kettle about to go off, something's gotta give if T.J. hopes to claw out from his own personal abyss.

The charmingly mild-mannered, heart-on-his-sleeves romantic lead he portrayed in 2009's "(500) Days of Summer" nowhere to be found, Joseph Gordon-Levitt continues to surprise with his seemingly boundless range as an actor. Look at his resumé and try to find two similar characters among them. You can't. Gordon-Levitt is nothing if not chameleonic, and his brazen, uninhibited, ultimately soulful turn as Hesher is another intensely accomplished performance to add to his repertoire, one that could have easily grated on the nerves but never does. With 2011's "Super" and now this picture, Rainn Wilson has set aside his comedic persona from TV's "The Office" for two dramatic turns of unexpected distinction and credibility. He's far better—and with a greater range—than one might have expected prior to these roles. When a flashback finally comes near the end that reveals just how much Paul has changed, the man he once was when his wife was alive now long gone, it's crushingly effective. Likewise, the glimpse of T.J.'s mom (Monica Staggs) is brief but unforgettable, hauntingly punctuated in her final moments with the use of Dion and the Belmonts' "Teenager in Love" as a care-free counterpoint to the calamitous event about to occur. In an instant, for Paul, for T.J., everything changes.

"Sometimes I feel like if I died today, no one would notice." So says a tearful Nicole, who is broke, stuck in a dead-end job, stranded in a broken-down car, and now with a ticket for illegal parking she has to worry about. It's a quiet moment between Nicole and T.J., but also one of the most poignant in the film, a window into Nicole's well-meaning, if troubled, soul. In her fifth release of the year, Natalie Portman (2011's "The Other Woman") is exceptional in the meek, good-hearted, somewhat against-type role of Nicole, a young woman who is taken by the kindness T.J. pays her following their first awkward chance encounter. Portman, who also produces, has truly come into her own recently, moving effortlessly from major studio productions within varying genres to smaller, adventurous indie movies. Her choices have been paying off big-time as she confidently segues into her adult career. Away from the big screen for several years, it is a treat to see Piper Laurie (1998's "The Faculty") again. She is exquisite, hugely funny and tragic in the same breath as T.J.'s grandmother Madeleine, an elderly lady who wants to make things right for her family but is constantly being betrayed by her age and health. A late scene she shares in her bedroom with Hesher is a delicate balancing act of tones pulled off with unassuming transcendence.

It is Devin Brochu (2009's "Ghosts of Girlfriends Past") as the hurting, strong-minded T.J., however, who is the secret, most vital weapon of "Hesher." It is through T.J.'s eyes that the story unravels and with him that the viewer agonizes and sympathizes with, and Brochu pulls off every demand asked of him like a veteran three times his age. The rebellion of a child who has lost his mother and doesn't know where to relocate the guidance she gave him; the reluctance of a boy to process and explain in words what he is feeling; the heartache that goes with opening up to someone and then being let down by unrealistic assumptions; the frustration of someone who is so consistently misunderstood—there are many more layers where those come from, and Brochu hits the mark on every one of them. Simply put, it is the most accomplished performance from a child actor since Max Records in 2009's "Where the Wild Things Are."

So, now—who, exactly, is Hesher? Is he a wayward drifter? A directionless slacker who loafs off people and just happens to make a few good decisions? Or might he be T.J.'s guardian angel, doing exactly what needs to be done to help out this child in need? Hesher's identity is left intriguingly open to interpretation, yet his purpose within the story remains the same. The climax, as Hesher sticks up for Madeleine and gives her a much-needed voice while finally, once and for all, pulling an outward catharsis from T.J. and his father, is a tear-jerking moment that earns its glimmer of sentimentality. By comparison, the last-scene tag is not wholly necessary and leaves a key subplot involving stolen money up in the air. These are miniscule debits, though, next to all that is done just right. As equal parts tough, touching and resolute as the renegade saving-grace of the title, "Hesher" is an uncommonly perceptive cinematic revolution.