The saturation factor of modern-day "truthspolitation" dramas and the genre's tendency to lapse into human-interest sentimentality more often than not has deadened the emotional currency that aforementioned idiom holds. After touring the stark convent of horrors that is The Magdalene Sisters, however, the notion that the story on-screen – a "semifictionalized" account of four testimonies from inmates of the notorious Magdalene Laundries – is rooted in reality carries a stronger weight than one could possibly imagine. This account of systematic torture and trauma doesn't just cut through the clichés and pitfalls of your average fact-based storytelling; it's fueled by enough genuine anger and outrage to slice straight to the bone.

The Magdalene Laundries were set up as sanctuaries for Ireland's "wayward girls," a broad term that could be applied to young women who'd given birth to a child out of wedlock, such as Rose (Dorothy Duffy); or who'd been raped, like Margaret (Anne Marie Duff); or who were simply considered a "temptress" because of their beauty, like the orphaned Bernadette (Nora Jane Noone). Run by an order of nuns bearing the beyond-ironic moniker Sisters of Mercy, these church-operated institutions preached spiritual penance through hard labor and corporeal punishment. The girls were not only forced to work long, silent hours in the convent's washrooms but were also regularly beaten, sexually abused, and imprisoned against their will; like Roach Motels, the Laundries were places you were checked into but couldn't check out of.

The trio of heroines we follow throughout the film suffers at the hands of the tyrannical Sister Bridget (Geraldine McEwan), a nun who rules the convent with an iron fist and feels no remorse in using it on her wards. She immediately strips Rose of her identity ("We already have a Rose here...your name is now Patricia") and sets about breaking the other girls' wills through sheer force. When Bernadette tries to defend the mentally deficient inmate Crispina (Eileen Walsh), she is whipped with a cane. Later, after an unsuccessful escape attempt, she's brutally shorn of her hair. The female populace of the convent's gray, bunkerlike walls are repeatedly told they're nothing more than "hookers and whores"; after hearing it burned into their brain like a mantra, most of them start to believe it's true. They're also told they will all burn eternally in hell. Some are convinced their sentence has already started.

History vindicates these girls by the time the credits roll, though to say their ending is a happy one would be cheating the preceding two hours. The film's singular power lies in its ability to tell its story so unsparingly, so unflinchingly, that the pain of the experience is never sugarcoated or given the glossy Hollywood treatment. Yet the matter-of-fact handling of the events never belies the core of rage aimed at both those who used the girls' souls as bargaining chips and the social structure that let them get away with it. In one devastating scene, the freshly violated Margaret watches the news of her defilement at a wedding spread among her male relatives, who quickly blame her for bringing shame to the family. Later in the film, she's given the chance to escape the convent through an open back door; after a passerby offers her a lift and a lecherous grin, she turns and reenters the grounds. Even freedom offers these "fallen" women nothing but pariahdom and oppression.

Credit goes to the actresses, mostly unknowns and all pitch-perfect in their roles, but it's the director, Peter Mullan, who fuels the film with a harsh, lyrical fury. A Scottish actor known for talking up leftist politics in interviews and taking risks in front of the camera, he uses an aesthetic for Sisters that's a blend of hyper-gritty earthiness and Bresson-like transcendentalism, which he describes as "realism, floating three feet above the ground." With nods to Ken Loach and Mike Hodges, Mullan's primary vision springs from the director's sense that the story he's telling needs to honor its tragic source. Even moments such as Margaret's revenge on a philandering priest, or her demand that Sister Bridget step aside in the convent hallway – scenes that normally would be played for maximum audience cheering – are laced with bitter defeat. Simply put, you'll get no easy salvation here.