Andre Techine, the gifted French filmmaker of "Wild Reeds" and "Barocco," is old enough to remember free love's garden of Eden. And old enough to remember when the first wave of AIDS crashed on French shores, precipitating the expulsion from paradise.

Set in the Orwellian year of 1984, Techine's "The Witnesses" unusually sensual and compelling, focuses on a close-knit trio whose relations unravel when the retrovirus slams their world and reconfigures it.

They are -- conveniently -- straight, bisexual and gay, and Techine has an admiring, never pornographic, fascination with their naked forms.

They are stunning Sarah (Emmanuelle Beart), a well-heeled writer of children's books and new mother remote from her infant; her dashing husband, Mehdi (Sami Bouajila), a vice squad detective of Algerian descent; and Sarah's best friend, Adrien (Michel Blanc), a doughy, gay physician who may well be emotionally closer to Sarah than is Mehdi.

Sarah and Mehdi have an open marriage with few complications; Adrien has open arms with few takers.

When the doctor forms a platonic arrangement with Manu (Johan Libereau), a fawnlike charmer he meets on the cruising circuit, it has unimaginable personal and professional repercussions for the three friends.

Techine's characters bathe in the "joie de vivre" of sexual adventurism, are stunned by its mortal consequences and at once grieve, study and chronicle those afflicted with the syndrome. And at once they grieve, fear and deny how AIDS may physically afflict them. Because each of the characters responds so differently, Techine examines the epidemic's human and psychological toll from multiple angles.

With a minimum of moralizing and maximum of human emotion, "The Witnesses" tells the parallel stories of those who died and those who live to bear witness. Techine uses jumpcuts to propel his story forward, gracefully editing these jagged sequences with rare fluidity.

I would have to watch the film again to fully parse the symbolism of its underwater and airborne sequences. But I suspect Techine is suggesting that love takes us deep in the ocean, high in the sky.