Sometimes the most fantastic movies are rooted in truth, and such is the case with "Olivier Olivier," by European filmmaker Agnieszka Holland ("Europa, Europa"). Holland read an intriguing article in a French newspaper, then further researched the story and used it as the basis for her fictional screenplay.

But don't think this is somehow akin to the typical made-for-TV real-life yarns we get in this country, those incredible true tales that receive mundane movie treatment on the networks every other night.

"Olivier Olivier" is stylishly directed by Holland and uncompromisingly uncomfortable in places, the story of a very dysfunctional family that is torn apart by tragedy . . . more than once. But they are already on the edge, with a violent, cruel streak that permeates every family member.

The film begins by setting up the family, disgruntled veterinarian Serge (Francois Cluzet) and his unhappy wife Elisabeth (Brigitte Rouan), who spoils her 9-year-old son Olivier (Emmanuel Morozof) incessantly, much to the chagrin of her neglected, mistreated older daughter Nadine (Faye Gatteau).

Nadine makes it a point to terrorize Olivier regularly, and since they live in the country with few neighbors, they are each other's primary playmates. Meanwhile, Elisabeth dotes on her son, living in constant fear that something will happen to him. Imagine her guilt when something does.

One day, Olivier is sent on his sister's bicycle to deliver lunch to his invalid grandmother — but he never reaches his destination. The family is soon ripped apart by the incident and ultimately Serge leaves his wife and daughter to try and make something of himself elsewhere.

Meanwhile, Officer Druot (Jean-Francois Stevenin), the local police investigator who has been trying to find some evidence of what happened to Olivier, is transferred to Paris. But he promises Elisabeth he will continue to track the case.

Now the action leaps forward six years as Druot comes upon a 15-year-old street delinquent (Gregoire Colin) who bears a passing resemblance to Olivier and seems to know quite a bit about the family. Druot concludes that this is the boy who disappeared and takes him to Elisabeth. When Serge is notified, he too returns home. And soon everyone is thoroughly satisfied that the boy is indeed Olivier.

Everyone, that is, except the now grown-up Nadine (Marina Golovine), who has been happy living alone with her mother, receiving more positive attention and not having to hear her parents constantly fighting. But now she knows things will change. And she's torn. Is she just jealous again, or is there some reason to seriously question whether her brother has really come home? The mystery gets darker and deeper as she tries to find out.

One of the things that is most striking about "Olivier Olivier" is its utter lack of sentimentality. Holland presents the film in a straightforward, matter-of-fact manner, allowing the audience to simply observe and draw its own conclusions. (Comparisons might be made to "The Double Life of Veronique" or "The Vanishing" or "The Return of Martin Guerre.")

As such, it's too bad that Holland feels the need to include an irrelevant witchcraft subplot involving Nadine, something that doesn't belong in this picture.

For most of the film Holland deals with tough material, from possible incest to homosexual rape with an unblinking attitude, and when the mystery is solved in the end, there is no happy conclusion. These people have been deeply scarred in too many ways to ever be anything but dysfunctional again. And it's a sober, somber realization.

That toughness is the reason for the R rating, with a fair amount of violence, profanity, vulgarity, sex and nudity.