CAST: Emile Hirsch, Kieran Culkin, Jena Malone, Jodie Foster, Vincent D'Onofrio, Jake Richardson

DIRECTOR: Peter Care

Say what you will about predatory priests--when it comes to controlling a boy's body and soul, there is nothing like a nun. Or so it seems to the pair of teen-aged protagonists in Peter Care's compelling but flawed adaptation of Chris Fuhrman's novel about a parochial school prank that takes a turn for the tragic. Sister Assumpta (Jodie Foster) may wear a habit, recite the Hail Mary and cherish her celibacy, but that doesn't make her a saint. She might even be the sadistic bitch the two pranksters think she is.

Whatever else she may be, Sister Assumpta is not a quitter. She isn't about to let the handicap of a prosthetic leg keep her from mounting her motorcycle and driving through the streets of a sleepy seventies town, performing God's errands as she goes. And back in the classroom, she is fiercely committed to saving the souls of her most sacrilegious students, Francis (Emile Hirsch) and Tim (Kieran Culkin).

How do the boys repay her missionary zeal? They cast her as the chief, alarmingly sexual villain in their secret comic book, an ambitious creation with bold, racy dialogue and grotesque drawings by Francis of not only Sister Assumpta but also Father Casey (Vincent D'Onofrio), a dum-dum jock about whom the only positive thing you could say is that he keeps his zipper zipped. Naturally, these salacious pages fall into the wrong hands, with dreadful consequences. Created by talented animator Todd McFarlane, this comic-strip part of the film--which repeatedly and lengthily interrupts the flow of the story--is meant to reflect Francis' emotional turmoil, his urgent need to make sense of his surroundings. But what the harsh, jarring images and sounds actually do is stop the story dead in its tracks.

Among the virtues of "Altar Boys" are the solid contributions of Hirsch, Culkin (who is reminiscent of the young Robert Downey Jr.), Jena Malone (as a precocious teen equally turned on by Francis and her own brother), and especially Jodie Foster, who miraculously conveys a touching fragility beneath her steely facade. If director Care is guilty of a mortal sin, it's not giving Foster more screen time.