As usual, the scene is the Shaming of the Shrew. On Stage 25 of the Paramount lot, Shelley Long and Ted Danson are replaying their Back Bay version of Petruchio and Kate. As barmaid Diane Chambers and barkeep Sam Malone, the most ambivalent amours in situation comedy, they are skirmishing in the war-torn Boston tavern that is the set of NBC's hit series Cheers. Sighs Diane: "Oh, Sam, is it so hard to tell me you love me?" Says Sam: "Right now, it's damn near impossible." As the run-through ends, Long exits through the office door; a moment later she calls from behind a piece of movable scenery, "I can't get out!" No one immediately rescues her and she calls out again, "I'm serious!" As a colleague starts off to liberate her, Danson intercedes. "Hey, guys," he says, "let's think about this."

Ouch! In Hollywood this season, only the set of Moonlighting has been prey to more rumors of backstage fits, fights and egos. "That is not a happy set," volunteers the head of production at a rival studio. After five seasons as the posturing and pretentious Diane Chambers, Long, 37, has decided to abdicate. She will film her last episode of Cheers next month. In terms of bad timing it might be the most notable series departure since Farrah Fawcett clipped the wings of Charlie's Angels after a year. Although Diane's tumultuous romance with Sam has driven her on occasion to a nuthouse and a nunnery, the couple was scheduled to wed at the end of this season. In fact, when Long announced her decision to the producers last December, the cast had already filmed an episode in which Sam and Diane got engaged.

Long's imminent departure has left the show in a lurch at the church. With shooting only three weeks away, a decision has yet to be made about the season finale. On the lot, the story goes that the producers are subtly conditioning the audience to dislike Diane so she won't be missed next season. Although it's unlikely that another actress will replace Long as Diane, the creators are considering a different female foil for Sam Malone. On and off the set, the response has bemused Long. "Sometimes people treat me like I'm going to die," she says.

Ironically, it was Long who popped the question of a marriage this season. Last July she and Danson pointedly asked the producers when Sam and Diane might marry. "Ted and I walked into the middle of a writing session, and I don't think we've done that more than once or twice in five years," recalls Long. The producers reminded her that she had previously hinted she wouldn't stay beyond the current season, when her contract expired. "It wasn't until the beginning of this season that I realized it was going to be very hard to say goodbye," says Long. Danson already had agreed to a one-year extension.

Just before Christmas Cheers director James Burrows cornered Long. He said a final decision was imperative to plot the rest of the season. She said, "Okay, I've been procrastinating because I am not looking forward to this." But making a decision took Long only two days. She requested a meeting with the producers and asked that Danson attend. "Ted said later that was his clue that I wasn't going to do it," says Long. "I said, 'Really? I would have wanted you there even if I'd said I would do another year.' " At that conference, Long abandoned her usual loquaciousness. "I knew it needed to be said and without a lot of words. So I just declared, "I have decided this will be my last season with Cheers."

Long is venturing into a no-man's-land that has already ensnared Farrah Fawcett, John Ritter and even Danson—the netherworld between Nielsen success and an uncertain film career. "Shelley has never hidden her ambition to move onto the big screen," says Disney exec Jeff Katzenberg. Still she hasn't been able to coast on such ill-received screen vehicles as The Money Pit and Irreconcilable Differences. But with her current hit, Outrageous Fortune, and a production deal at Disney, says Long, "Movies seem to be opening up to me now, and I want to take advantage of that." If others think Shelley is at a career crossroads, she does not. "I've already crossed the road. I mean, I've made a choice. Cheers will do just fine without me."

If God hadn't invented anxiety, Shelley Long would have. She worries. Years ago she began bringing her own tape recorder to interviews so that she could analyze her answers afterward. "Nothing is perfect," she explains, "as much as I would like it to be." She worries that talking about her improvisations on the set of Outrageous Fortune will slight the screenwriter. She worries about discussing a Disney film while eating lunch in the Paramount commissary. She worries about what she says as soon as she says it. Of co-star Bette Midler, she notes, "Gee, I think I observed a level of fun and lightness in Bette, and that's something I strive for, you know." Already, she is worried. "Is 'strive' the word we want to use?" She laughs nervously. "I don't know. Please write I laughed when I said that." She is worried about saying that too.

Her questioning approach was a potential hazard while shooting Outrageous Fortune. Like the rivals in the movie, Long and Midler favor different approaches to acting. "If Shelley leans more to the thought-out," says Fortune director Arthur Hiller, "Bette leans more to the instinctual." Long's formality struck Bette too. Says Midler, "Shelley has an old-fashioned quality that studio people used to have. She has a very pretty speaking voice and she has a lot of personal dignity." Their contradictory methods led to reports of conflict during production. Although the actresses deny that they had problems, they don't pose as such good friends either. "I don't know her well," says Midler.

In a town where "perfectionist" is usually a euphemism for "avoid this person at all costs," Shelley Long has, by her own admission, a reputation for perfectionism. For this lady, slurring her consonants would be a sin. "I ask more questions [about character motivation] than some actors," admits Long. "Maybe more than most, but not all! There's got to be another actor out there that asks more questions. I know it drives people crazy; it drives me crazy." On the collaborative set of Cheers, she says, "I probably ask a few more questions than Ted. And I know it is probably very aggravating at times."

Charting a precise course extends to her off-camera life as well. Because she was committed to Cheers, she carefully planned the birth of her 23-month-old daughter to occur during the show's hiatus. "Maybe you could find that a bit much," she says. "But I wanted to do it in a fair way—one that was fair to the show and to my family." Two weeks after giving birth, however, Long was giving another performance. In New York she started production on The Money Pit. "My family understands that my career is a high priority as well," she explains. "It isn't always the most important priority. But even my daughter, as young as she is, knows when Mommy is working. I'm doing this because I'm having fun with it, and she can find something she has fun with too." Leaving Cheers is intended to give Shelley more time with her family, but she currently has a window of only two weeks between shutting down Cheers and starting up her next Disney movie. It's called Hello Again, a comedy in which she plays a housewife who dies and gets a second chance at life.

Watching Long at home you see a woman who leaves very little to chance. Shelley is sipping tea in the kitchen of her Pacific Palisades homestead, which features most of what has eluded Diane Chambers. Upstairs the nanny tends to daughter Juliana. Over a desk in the den hunches her husband, Bruce Tyson, 34, an investment counselor. Quiet-spoken and easygoing, Tyson functions as a calming influence on his wife. "Let's face it, anything I do I want to be absolutely the best," says Shelley. "So I was lucky I was able to find a husband who is very patient." Into the kitchen trundles Juliana. "There's my sweetie," says Long. If God hadn't invented Norman Rockwell, Shelley Long would have tried.

Whatever it is that she starts—or finishes—Shelley Long wants a happy ending. As she continues to tell the producers, she wants Sam and Diane married. And when she talks about that odd couple, there is in her pronouncements an uncommon passion. "I think Sam is the only impulsive, hot love that Diane will ever have. She might have a bit more, uhh, sedentary—is that the word I want? I don't use these words as well as she does—well, she might have a more grounded kind of love with someone else. It was great to see them get engaged, wasn't it? It was neat."

In another woman the incongruities would operate on a collision course—but not in Shelley Long. Here is a sophisticate who punctuates her pronouncements with "neat" and "gee," souvenirs of her Midwest childhood. Here is an actress who looks like the girl next door and acts like a proper patrician. Here, for instance, is Long pep-talking to her hairdresser and make-up artist after a long day of movie promotion: "I think we really did good work today. What we did this morning was fine, but this afternoon was even better. We really worked together as a team. That's very important, so thank you." As with Diane Chambers, her tone can ricochet in the same sentence between the polite and the patronizing, the sincere and the saccharine. This isn't a case of the lady or the tiger. This lady is the tiger. Sanguine about the past, she says, "It's time to move into the next phase. I've studied the question [of leaving Cheers] carefully because I knew that was only fair to me and the Cheers people and the fans. I know many of them have made their displeasure known. People who work on the show have said their friends told them, 'You tell Shelley that we're really disappointed.' And I feel bad because it's going to be hard not to see Diane with Sam. Did I say this already? Cheers will do just fine without me."

Maybe now, Shelley Long will stop worrying.