The most recent round of TV spots for Lee Daniels' Precious seem designed primarily to counteract the only element of bad buzz in its considerable word-of-mouth success: that it is a downer, depressing, sad, etc. So Lionsgate put out an ad with upbeat music, smiling characters, and voice-over narration about how inspirational and uplifting the movie is. It is, perhaps, not the most honest television advertisement you've ever seen. Precious is, in fact, inspirational and uplifting, but it makes the viewer walk through fire to get there. It is a classical tragedy in the Greek sense, and runs its characters (and viewers) through a wringer of pity and terror on the way to its devastating catharsis.

Gabourey Sidibe plays the title character, a 16-year-old still stuck in junior high, pregnant with her second child. She shares an apartment with her mother (Mo'Nique), a chain-smoking bully; both her mother and (mostly off-screen) father subject Precious to a stream of physical and mental abuse. Precious creates elaborate fantasies to escape from her impossible reality, dreaming of a glamorous and happy life that she fears she will never know. In desperation, her school principal sends her to an alternative school, where she is taught basic reading, writing, and arithmetic by Ms. Rain (Paula Patton); the interest and encouragement of a genuinely positive adult figure opens the young woman's eyes to what her life could be.

Hearing a synopsis like that, you can imagine the clichés and pitfalls that it could fall into; in the hands of the wrong writer and director, that story's got the makings of a Lifetime movie. Luckily, Precious has the right writer and director. Geoffrey Fletcher (adapting the novel Push by Sapphire, as awkwardly indicated by the film's full title) isn't afraid to make the centerpiece scenes of abuse and psychological terror (like Precious' return home with her newborn son) truly harrowing--they gobsmack the audience like blunt instruments. But he (and director Lee Daniels) knows that an audience needs variation from this kind of grim tragedy; we need escape valves and distractions, which the picture (thankfully) provides.

Even when the writing is spotty or obvious, Daniels' instincts are mostly good; Precious' fantasy life is richly, entertainingly drawn (and slickly shot, indicating that the picture's gritty, low-fi aesthetic is a stylistic choice rather than a necessity), though a couple of those sequences are goofily broad rather than poignant (I'm lookin' at you, foreign film on Mama's TV set), and somewhat out of place. Indeed, some of the tonal shifts are a bit too wild to play, though Daniels' experimentation is welcome and certainly doesn't derail the enterprise.

In many ways, the heart at the movie's center are the scenes with Precious and her classmates (both in and out of school), which have a loose, offhand, improvisational vibe that goes a long way towards levity. Those scenes are anchored by the considerable warmth of Patton, an actor whose previous work (most notably as window dressing in films like Déjà Vu and Idlewild) gave no indication of the depths of her talent. For that matter, who knew Mariah Carey (more than holding her own in one of the movie's toughest scenes) had a performance like this in her, to say nothing of Mo'Nique, who is simply electrifying.

All of them are in support of Sidibe, in (astonishingly) her film debut, turning in a beautifully modulated and stunningly controlled performance. She is completely shut off as the picture begins, in that particularly unforgiving way that hopeless teenagers are; her mouth is locked in frown, and it hardly seems that any light is making its way into her eyes. But as the film progresses, she slowly becomes comfortable in her own skin and develops, delicately, tentatively, into her own person; even her voice-overs become more confident and funny ("They talk like TV channels I don't watch"). That kind of transformation is stunning, particularly in a first-time performer--we're with her, all the way, and when she falls apart, it is shattering.

If the first half of Precious is tenuous, the second is unflinching and powerful, unrelenting in its sorrow yet simultaneously moving and forgiving. It is a bold, heartbreaking picture, and entirely worthy of the considerable praise it has received. It is, make no mistake, difficult viewing. But some films are worth the effort.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.