After Mary McDonnell appeared in independent filmmaker John Sayles' mining epic "Matewan," the two took in a play in New York. "He leaned over at intermission," McDonnell recalled in a recent interview, "and said, `So I have this idea . . . about this really bitter woman.' "

Not much to go on, but McDonnell knew Sayles' reputation for creating intelligent, involving movies from modest ideas and budgets. The idea popped up in conversation between the two over the years, until, McDonnell said, "When I was doing `Grand Canyon,' he and Maggie (Renzi, Sayles' producer) called me and said that they could shoot this movie in about a year. I said, `The only thing is, I haven't read it yet.' And he said, `Well, I haven't written it yet.' "A script came soon thereafter, however, with that core idea eventually evolving into "Passion Fish," which opened Wednesday in a limited one-week run for Academy Award consideration. McDonnell stars as a former soap-opera actress who is involved in an accident that leaves her a paraplegic. She returns to her home in rural Louisiana to soothe her broken spirit. She hires a nurse (played by Alfre Woodard), and both women help heal one another's wounds, both physical and psychological, and fall prey to the seductive lures of bayou country.

"It's a part where you have to play a lot of roles," Sayles said about McDonnell's performance. "You have to play a person who is disappointed in her life and wants to make everyone around you miserable, but you also have to be very gracious. The graciousness is an act, and it's a very Southern thing, but it's also very charming. The trick is in the layers - when is she hurt and showing it, when is she hurt and masking it?

"Mary's a really good actress - she has that combination of being able to listen onscreen and still be powerful. With some actors, you never feel they're listening to anyone else, and they never play characters who really listen to anyone. But it was important to show that she stops thinking about herself and gets interested in Alfre. And she certainly has the necessary power for the emotional scenes."

It's the latest in a string of high-profile projects that McDonnell has appeared in since receiving an Oscar nomination for Best Supporting Actress for "Dances With Wolves." But after playing further supporting roles in "Grand Canyon" and "Sneakers," McDonnell was keen on the opportunity to play what she found to be such a complicated character in a rich, layered story.

"John sends you a lot of autobiographical, stream-of-consciousness stuff for you to absorb about the character," she said. "It would be hard to imagine receiving this information from anyone else. It would be like - `Whoa, back off. I don't want your ideas of who I'm playing."'

But she trusted Sayles' instincts, and was astonished at the detail with which he had delineated her character. "He gives you a historical, political, sociological background, and the actor is so used to working on the psychological, spiritual and emotional plane, that I just find it all stimulating. That helped me appreciate how large the movie actually is." Sayles got the idea for the story 20 years ago working as a hospital orderly and observing the dichotomous relationship between patients and their private nurses.

To prepare to play a paraplegic, McDonnell conferred with a therapist at Northridge Hospital in the San Fernando Valley. "I was astonished by what it did to me emotionally once I stopped using these muscles in my legs, I started having emotional reactions that were very hard to take."

While shooting the film, "I got out of that wheelchair as fast as I could (between takes), as opposed to other people I've heard about who stay in it forever," she said. "It's so intense for me in the moments I'm working, and it's very hard for me to keep a distance between the character and myself. So I have to do everything I can when I've finished working to drop it . . . so that I don't go nuts."

Though she was an Obie-winning stage actress with solid New York credentials, McDonnell said her life and career really only turned around after "Dances With Wolves." (She remembers having to take a job in a Greek restaurant a mere month after winning the Obie). Today, she can recall with a smile, she initially didn't want anything to do with what she heard being touted as "a cowboy-and-Indian movie" for which the producers weren't even providing advance scripts for auditioners.

But upon going in for her reading, she said, "It was so clear to me that this was new and it was special and important and I had a very strong reaction to it, just in reading it. I always felt it would have an impact - I had no idea it would be the commercial success.

"I knew people would need this. I knew people would find this healing, and I knew it would tap into our collective guilt, and we as a country would be able to think about something we've been trying to shove away for a long time. I was just nuts about it from the get-go."

With "Passion Fish," McDonnell is once again being touted as a possible Oscar contender, this time in the Best Actress category, a benefit she says was not on her mind when she began working on the film.

"I thought this was a great role, an opportunity to see what it's like to carry the throughline of a story, which I've never done," she said. "I've always been in support of the throughline. This is an opportunity to work with a director I trust in order to experiment with that responsibility. That's what excited me. Plus, I was excited to play bitterness and all that. Because I have a lot in me - my dark side is very underexplored in film and I would like to get it out there.

"I didn't think at all about the Oscar question until people started talking about it after they started seeing the film. And then, you try very hard to not - of course, I would be lying to you if I said it doesn't feel good to have people bring it up. Peer recognition, it's wonderful to feel it. But I wouldn't sit down and consciously think about it ahead of time."

With McDonnell, you're inclined to believe her. Despite her mounting successes, she doesn't betray a trace of ego - unlike some artists, she doesn't refer to herself in the third person, as if she's trapped outside her public persona or has simply become a commodity. And unlike scores of actors who mumble vagaries about "choices" or "trying different things," McDonnell cogently and with great depth discusses the craft of acting.

That would seem to make her sound material for an acting instructor, and in fact she does teach at the Coast Playhouse in Hollywood. There, she has discovered that the industry is sending a wrong, and potentially deleterious, message to budding talents.

"The thing that comes up over and over again in class is that this town seems to give you the signal when you come in that you need to adjust your style to Hollywood before it's interested in what you have to offer," she said. "And that is such a destructive idea to the creativity of a person. And I've found that that is the thing that will destroy your success in the long run."

McDonnell herself has by her own admission been in and out of Hollywood a number of times, escaping when it became clear to her that the industry's attitude toward her - or vice versa - was becoming unhealthy. She's only lived here for a year in this most recent stint, committing to Los Angeles because of her burgeoning interest in producing films.

One reason producing is looking so appetizing to her, she said, is that it will help her become a stronger advocate for finding quality material, not just for actresses, but all performers. McDonnell doesn't necessarily buy the pessimistic argument that this year's paucity of strong lead roles for actresses reflects a downturn for the profession. She points out that it also reflects a turn away from traditionally sexist portrayals of women in lead roles.

"Maybe what's happening is we're gearing up for a change," McDonnell offered hopefully. "There's a transition being made here. There might have been plentiful, large roles for women in the past, but in my opinion, they weren't necessarily where we need to be as women in film. Maybe what we've done is we've played out the old tune, and we're ready for something new, but we're simply in a transition."