There is one scene in Ann-Margret's film repertoire that says it all.

It's a bedroom scene, in the 1965 "Cincinnati Kid." But it's not her sultry purr or sex-kitten strut that is so quintessentially La Margret. It's something else.

She kneels on the bed, clad in a scanty negligee, a jigsaw puzzle spread before her. She takes a piece and places it on the puzzle. It doesn't fit. She tries forcing it. It still doesn't fit. Karl Malden, her gambler husband, scowls at her, telling her to give up. She cocks an eyebrow, picks up a nail file, shaves away one side of the piece and bangs it into place with her fist.

"Now it does," she coos.

Determination. That and a sly vulnerability are what make Ann-Margret, 43-year-old motorcycle-riding grandmother and veteran of 38 movies, one of the most durable stars Hollywood ever dished up.

Never mind all the bimbo parts ("Kitten With a Whip," "Bye-Bye Birdie," "The Pleasure Seekers," "Bus Riley's Back in Town"), the steamy gyrations ("Viva Las Vegas") or the tongue hockey matches with leading men from Steve McQueen to Elvis Presley, Joe Namath to Jack Nicholson.

"I knew I had something to offer in the way of dramatic ability a long time ago," she says, sipping tea in her Washington hotel room the other day. She is in town for the opening of her latest film, "Return of the Soldier," costarring Glenda Jackson, Julie Christie and Alan Bates, which premiered last night at the Fourth International Women's Film Festival.

It is another piece in the puzzle, a breakthrough of sorts for the Swedish-born actress, who is cast as a dowdy, aging spinster -- a part, she says, for which American directors would never have considered her.

"It was a challenge not to stand out like a sore thumb, but I never felt intimidated," she says, referring to her stellar supporting cast. "Did I surprise people? I just think it's so funny," she says, laughing with gusto. "That word has been used so many times. I love surprising people."

She is wearing a short sweater dress over tan leather boots. Her pale, strawberry hair is fine and shoulder-length, her skin the texture of peach yogurt. On her left hand is a heart-shaped diamond JoJo Starbuck could skate on.

"I was extremely serious about my work," she says in her familiar, little-girl whisper. "Always. The roles were fluff."

Now the roles are chuck steak.

It began in 1971, when Mike Nichols chose her for the part of overweight, victimized Bobbie Templeton in "Carnal Knowledge." She was nominated for an Academy Award and won the Golden Globe. Then came a daring role in "Tommy," another Academy Award nomination and the Golden Globe for Best Actress. More recently she starred in two made-for-television films -- as a cancer victim and mother of 10 in "Who Will Love My Children" (to be rebroadcast tomorrow night), and last year's grueling role of Blanche DuBois (which she nicknamed Blanche Du Bonkers) in Tennesee Williams' "A Streetcar Named Desire."

Her determination to be taken seriously was rewarded with two Emmy nominations. It was the same firmness of purpose that got her back on her feet after being thrown 22 feet from a Lake Tahoe stage platform in 1972. The fall smashed her face and nearly killed her. Coincidentally, her father was dying of cancer at the time. Ten weeks later -- "I had to prove to him that I could do it" -- she was back on stage. She later won a settlement for $1.5 million from the hotel. "I still get a sick feeling in my stomach when I look down," she says, glancing toward the window. "I see that image. Of the floor."

It's the same driving force that kept her going, show after Las Vegas show, film after film, television special after television special. There was a nervous breakdown in 1980, and a year later her husband and mentor of 18 years, Roger ("77 Sunset Strip") Smith, was diagnosed as having myasthenia gravis, an incurable, deteriorating neuromuscular disease.

Smith walks into the room. He looks tan and fit. "Unbelievable," whispers Ann-Margret, knocking the wooden end table with her knuckles. "He's in remission."

Whatever talent she may lack -- no one would confuse her with Meryl Streep -- she has more than made up for in hard work. She is known among her peers as tireless performer, a total professional. "I've been known to be obsessive," she admits.

But there's one thing even Ann-Margret's herculean determination can't overcome, a piece of the puzzle that will not fit -- her inability to have children.

"We've been trying for 13 years," she says. Her husband has three children from his first marriage, and Ann-Margret is already a grandmother.

"I have gone so far as to have an ovulation pump. A friend of ours in Sweden sent one to mother, and she gave it to me. I gave it to my gynecologist." A needle inserted in her abdomen, she says, injects hormones that enable a woman to tell when she is ovulating. It goes zzzzzz. I felt like a robot!"

She says she has tried everything. Last month, she finally stopped trying.

"My doctor just laughed at me because I came in last week and I was feeling so chirpy and so happy and I've gained some weight, and he said, 'You're going to get pregnant.' "

She says she'll wait and see and, in the meantime, try to relax. She and Smith are flying to Aspen next week for some skiing, then there's more traveling on the agenda.

She says she will never play Vegas again.

"It's really too stressful. We found that even concerts, going from city to city, is too stressful for Roger."

She has been off the stage for nearly two years. Can she live without the applause?

"That's interesting," she says, staring into space. "It's interesting because I don't miss it. For the first time in my life, I guess. I get it now from doing a role, from acting. I'm gratified when I come home from a day's work and I've done the best I can in portraying a character. I get that same feeling of gratitude."

She places her hand over her heart. "It's much more of a peaceful feeling going on in here. I'm very lucky," she says, knocking the end table again, "that I'm not crazier than I am."

Her obsessiveness has found a new outlet recently -- exercise.

"Roger asked me what I wanted for my birthday. I said I really wanted some gym equipment. So he got 11 stations of Universal equipment and now we've gotten two or three others and now we do it four days a week and I even give instructions to my friends on Saturdays!"

She throws her head back and laughs lustily. She says she also enjoys scuba diving, but since the accident finds it uncomfortable. "All these bones were crushed, so it's not very smart of me to go into the ocean because it the water gets all up in there."

There are no visible scars on her face.

"But when I'm very thin, you can see part of the indentation. You can feel it. Here, feel this side." She takes a reporter's index finger and guides it along her right cheekbone. "Now, feel this side." She traces the left cheekbone. There is a small dent where a bone should be. "These bones are gone forever. And every now and then," she laughs, setting her mouth in a frozen smile, "mah jawww locksh in pwace."

She also has a tremor. She holds out her right hand. It shakes violently. It only happens when she's tired.

No, she says, she did not see the recent special on Elvis, celebrating his 50th birthday.

"I can't watch anything," she says, lowering her gaze.

Was she in love with him?

"I don't want to get into that."

There is a long silence.

"He left before his time," she says, eyes glassy with tears. "Way before his time."

Her next project will be starring in a made-for-television movie about a Midwest teacher who is raped and decides to keep the baby. Again, not a typical role for a woman who was once considered a joke in Hollywood.

"I really feel for people who come out of a different area of the entertainment world and go into drama. It's much easier for someone to come out of the ranks of the New York theater, Off-Broadway or whatever. If you do that, you're considered a dramatic actress."

The way Ann-Margret did it, "it takes more time for people to think that they're serious about it. I don't know why that is."

But she says she's happy. She says she's relaxed.

"I just want to do things I want to do," she says, looking very, very determined.