AT THE BEGINNING of "The Mother," May (Anne Reid) might as well be dead. Her husband, Toots (Peter Vaughan), just succumbed to a heart attack. Now in her sixties, she has nothing left in her life. She doesn't get along well with her grown children, Bobby (Steven Mackintosh) or Paula (Cathryn Bradshaw), or her grandchildren. And it seems to be understood that she'll submit to a slow descent into oblivion.

But in this bracing but superb adult drama, May refuses to lie down in the coffin that has been prepared for her. She embarks, instead, on a journey into the unknown, in search of her unrealized sexuality. She does this with enormous courage, despite the horror of her family.

His name is Darren (Daniel Craig). A muscular, bearded man in his thirties, he's building an addition to Bobby's house. She doesn't pay much attention to Darren until she spends some time at Paula's, where she witnesses him having sex with her daughter.

Something awakens in May. At first determined to talk Darren, who's married, out of an unhealthy relationship with Paula, May finds herself increasingly attracted to him. After all, May reasons, Darren's affair with Paula is a disaster. And Paula, a tortured and over-needy person, has already confided to her mother that she wants out.

Darren, a cocaine user, the father of an autistic child and an adventurous soul, is easily seduced. He's thrilled to indulge in this unusual opportunity. They start a clandestine sexual partnership, full of laughter, passion and seeming honesty. But the bliss is inevitably short-lived; Paula wants back into the relationship with Darren. Pressure builds on many fronts. It isn't long before things have to be revealed. At that point, May and Darren have to assess what they have between them, or what they don't.

Written by Hanif ("My Beautiful Laundrette") Kureishi, and directed by Roger Michell (who also directed "Persuasion" and "Notting Hill"), the movie is admirably unflinching and unconventional. This isn't some rosy Italian number about the older, vivacious woman and the adventurous young lothario who discover a new affirmation for life, all this to swelling music. It's meaner and truer. It's about loneliness and the misguided grabs at love that many people make to stop that empty feeling. Almost everyone is forced to acknowledge their true motivations, as ignoble as they may be. In a way, this is a farce without punch lines, and its seriousness never lets up.

As you can imagine, this is a British movie. It couldn't have been made by an American studio, which surely would have demanded the audience understand everything about the characters and, of course, identify with someone. "The Mother" isn't so frivolous. It becomes, among many things, an investigation into everyone. Paula blames her parents' lovelessness for her lack of success. May has her own frustrations and disappointments. Darren's soul is can-opened as well. It's apt to leave you oddly sober, if not a little disturbed, but deeply enlightened. Finally, we have found ourselves in a movie where the characters are free to blunder, even if it means turning their backs on us. There's powerful liberation in that, all around.

THE MOTHER (R, 112 minutes) -- Contains mature themes of sexuality, obscenity, drug use, nudity and sex scenes. At Cinema Arts Theatre, Cineplex Odeon Shirlington and Landmark's E Street Cinema.

Anne Reid as May and Daniel Craig as Darren in "The Mother."