The title of “The Magdalene Sisters” obviously has a double meaning. It refers on the one hand to the order of nuns that, until very recently, served as the unofficial warders of wayward women–unwed mothers and girls deemed dangerously promiscuous–in arch-Catholic Ireland, where men were allowed almost any sexual indiscretion but females were expected to be free of the slightest suspicion. But it’s also meant to identify the young inmates at the convent who build a strong sense of camaraderie in the face of their harsh treatment. Written and directed by Peter Mullan, who developed the story from the recollections of women who had actually spent time in the none-too-charitable care of the nuns, the film tells a story that, in its general outline, follows a fairly predictable path, but conveys enough specificity of time and place to give it greater punch than you might expect.

The script, set in the mid-1960s, is constructed around the experiences of three girls. Sweet, demure Margaret (Anne-Marie Duff ), raped by her cousin at a wedding reception, is shipped off to the nuns to avoid family dishonor. Sultry orphan Bernadette (Nora-Jane Noone) is dispatched there simply because she’s considered too great a temptation to the local youth. And Rose (Dorothy Duffy) finds herself there after she gives up her illegitimate child for adoption and is effectively disowned by her parents. Among the other captives, all of whom work long hours in the convent’s profitable laundry, the most notable are Crispina (Eileen Walsh), a mentally-challenged girl who dreams of conversing with the son who’s in the care of her sister and is taken advantage of by the local priest, and Katy (Britta Smith), an elderly resident whose feeble-mindedness and religious mania foreshadow what might await the younger women.

Presiding over the operation is the formidable Sister Bridget (Geraldine McEwan), a woman convinced that her brutal methods are in the service of a higher power. A few moments suggest that her harshness extends to her rule over the other nuns, though one sequence–involving a private screening of “The Bells of St. Mary’s”–suggests that she also has an incongruously sentimental side.

As might be expected, the film concentrates on the humiliations that the nuns’ charges endure in their custody. These range from a sinister “renaming” ceremony to an unsettling confrontation between the girls, naked after a shower, and a nastily jocular nun and to Bridget’s smugly self-righteous shearing of the hair of particularly recalcitrant girls. These episodes engender the requisite indignation, and make all the more satisfying the girls’ occasional victories–a bit of revenge taken against the lecherous priest, for example. But the real emotional release comes with the eventual escape of some of the characters from the nuns’ clutches. The sense of triumph is tempered, however, by the tragic fate of others.

At a time when the despicable past practices of some members of the clergy, especially in terms of their treatment of the young, are being revealed, this portrait of what amounts to institutional abuse (in collusion with a religiously monolithic state and a male-dominated culture) can’t help but carry considerable force. And Mullan’s treatment of it is expertly judged to evoke the classical reactions of pity and terror; he manages to keep even the most extreme moments within bounds, so that the level of manipulation doesn’t become intolerable, and he often interjects a hint of mordant humor to leaven the darkest moments. He also secures excellent performances from his young, largely untested actresses–Noone is especially fine as the sullen, beautiful Bernadette–and a rich, multi-textured one from McEwan as a monster who actually believes herself a saint. Smith won’t gain a similar degree of recognition, but in many ways her performance is even more remarkable, because while she’s a basically peripheral character, her wrenching final scene is in many ways the most artful summation of the horror the Magdalene operation represented. Mullan himself appears in a forceful cameo as the furious father of a girl who successfully escapes the convent–though only briefly.

“The Magdalene Sisters” is a small film, but Mark Leese’s production design is excellent, with excellent period detail and use of locations. Nigel Willoughby’s cinematography, with its emphasis on blues and greys, is superb as well, as is Craig Armstrong’s supportive score. Though the picture that might sometimes seem a bit obvious in its point-making, it’s mostly quite successful in its indictment of a cruel ecclesiastical institution, a disgracefully compliant government, and a society that made both possible.