Coline Serreau's "Chaos" defies categorization. It is an exciting film--part thriller, comedy, revenge tale, and feminist drama, blended together with compelling finesse.

Hélène (Catherine Frot) and Paul (Vincent Lindon) are a seemingly dull bourgeois couple--always busy, always late, professionals with a terrific apartment--whose lives are forever changed when they witness the savage beating of a prostitute (Rachida Brakni) on the hood of their car. They do nothing. Paul locks the door to his fine automobile, and when the pimps run off--the beaten woman lying bleeding and unconscious in the street--the shaken couple take the sullied car directly to a car wash.

What horrible people, you think. Their behavior is horrible, and from the comfortable vantage of their well-appointed Parisian home, they physically look horrible: complacent Paul with his puffy face and his business suit and mousy Hélène with her muted, conservative clothes and dull brown hair. She is thin and pinched, a woman not to be noticed in a crowd.

But Hélène will surprise you. Hélène surprises herself. She tracks down the prostitute, Noémie, to an ICU unit in a hospital and devotes herself to the stranger's recuperation--at the expense of her marriage, her career, and her spoiled, beautiful son Fabrice. Hélène stays by Noémie's bedside, day and night, talking to the comatose woman, bathing her, massaging her, and feeding her. As Noémie's recovery progresses, Hélène also protects her from the pimps who haunt the hospital corridors. Hélène, in front of your very eyes, becomes extraordinary.

And this is just the first half of the movie. Coline Serreau also explores the comedy/animosity of the sexes. Paul, for instance, does not miss Hélène in her absence, but he desperately needs a wife. He cannot iron a shirt, wash a dish, or make a bed. Further chaos ensues when their son Fabrice moves back home after being kicked out for his own callous, sexist treatment of his lovely young girlfriend. Like father, like son. Their fast domestic demise is flat-out, slapstick funny, but also resonates with a deeper sadness. Is this how things still are? In "Chaos," men want their clothes cleaned, their sexual appetites fulfilled, and their food prepared--and these are the good guys. At worst, they are raping, beating pimps who buy and sell women like cattle.

When Noémie finally recovers, she has her own complicated narrative to tell. Rachida Brakni, who won the Cesar Award for promising newcomer for her performance, has the stunning good looks of a brooding, dark-skinned Julia Roberts. Serreau skillfully reveals the common ground between the two women, despite the vast differences in their backgrounds and age. She covers a lot of ground in "Chaos," and after the careful depiction of Hélène's world, the rush of details and complicated plots twists used to develop Noémie's story can seem like a bit much. No matter, though, because the end delivers. All the pieces fall together, and the closing shot is warm, rich, and deeply satisfying.