To get an idea of whether there's even a chance you'll enjoy "The Butcher Boy," just consider this inside joke: The woman chosen by filmmaker Neil Jordan to play a fantasy version of the Virgin Mary is controversial musician Sinead O'Connor.

That bit of irreverence is typical of the tone of this uneven but at times amusing dark comedy, based on Patrick McCabe's 1992 novel. And be warned, there is even more outrageous humor in the film - much of it based on religion.What else would you expect from Irish filmmaker Neil Jordan, who has made a series of deliberate decisions to shock moviegoers (such as the shocking character revelation in "The Crying Game")?

From that perspective, "The Butcher Boy" is in good company.

Jordan and McCabe collaborated on this adaptation, which follows the misadventures of 12-year-old Irish boy Francie Brady (newcomer Eamonn Owens). The product of a broken home - which includes his alcoholic musician father (Irish character actor Stephen Rea) and abused mother (Aisling O'Sullivan) - Francie has a hard time distinguishing fantasy from reality.

Consequently, his "pranks" - many of them at the expense of nerdy classmate Phillip Nugent (Andrew Fullerton) - become more and more mean-spirited, much to the chagrin of his disapproving neighbors, especially Phillip's snooty mother (Fiona Shaw).

Eventually, Francie goes too far and is sent to a strict Catholic reformatory, where his dementia grows even more severe. He begins seeing visions of the Virgin Mary, who validates his delusional claims.

When he's finally released, it's a different village he returns to. His "blood brother" Joe (Alan Boyle) is now hanging out with Phillip and has no time for him, a betrayal that leads to dire consequences.

Much of the film rests on Owens, who is more than up to the task. His portrayal of a youth walking the line between sanity and madness is astonishing.

However, there are times when Jordan pushes the film in some very weird and inappropriate directions. And it would have been nice to get a little more perspective on the boy's family situation.

"The Butcher Boy" is rated R for profanity, violent fist-fighting and some gruesome hog-slaughtering scenes, as well as vulgar gags and jokes, and gory special effects.