The long-distance operator said: "Will you accept a call from Mr. Dermot?"

At the other end of the line, Dermot Mulroney chuckled. Okay, so his full name isn't exactly a household word yet. But it probably will be, if he keeps getting roles as good as the ones he's played so far.

After all, he's been in show biz only for a year and a half and already he's had leads in two television movies, appeared in two other shows, and has made two theatrical films, Blake Edwards' "Sunset" and "Survival," both yet to be released.

Some actors wait years for any one of these breaks, but for Mulroney -- whose mother says he has "the luck of the Irish" -- the transition from Alexandria, Va., to Tinseltown has been relatively effortless.

Saturday at 8, Mulroney will turn up in "Long Gone" on Home Box Office, a comedy-drama about a struggling minor league baseball team starring William Petersen, Virginia Madsen and Larry Riley.

Peterson plays the pitcher/manager of the Tampico Stogies, Madsen the blonde who forgets the words to the National Anthem and decides to become his girl friend, and Riley the team's savior, a catcher who can slam the ball out of the park but has to be protected against the Ku Klux Klan.

Mulroney plays a small-town Alabama boy who is hired as second baseman and helps the dismal team get back into the win column. He becomes involved with the virginal Esther (Katy Boyer) who falls for him but prays they can keep their passions under control. They can't, of course.

Like most sports films, "Long Gone" builds to the key game. This one also ties up the romances with an arch of baseball bats at the infield.

Growing up in Alexandria, Dermot Mulroney never played much baseball. He was coxswain for the T.C. Williams High School crew team and played his cello in as many as six area youth orchestras at one time. "People used to say, 'Didn't you do any sports? Didn't you play baseball? What are you, a fag?'" He laughed, and he had the last laugh as well. "Yeah, I got to do both. In 'Long Gone' I'm a hot-shot second baseman, the hot-shot rookie," he said rather gleefully.

Dermot wasn't the only Mulroney in "Long Gone," as it turned out. When his character, hot-shot second baseman Jamie Weeks, gets married to his pregnant girlfriend, his mother attends the wedding. No one had been cast as his mother -- she has no lines -- so Mulroney suggested that his real mother come to Tampa, Fla., to appear in one scene.

"She's sort of at the bottom of a frame of a crane shot," he said. "I was just a body in a chair," agreed Ellen Mulroney, who recently appeared in the Alexandria Little Theatre production of "A Man for All Seasons."

Ellen and Michael Mulroney raised their brood of five in a large old house on Maple Street, in Alexandria's Rosemont neighborhood. Their middle child, Dermot, remembers the house as "perfect for high school parties," especially one memorable New Year's Eve bash. He left for college before they moved to another house in Old Town.

Ellen Mulroney recalled her middle child as "highly competitive," and she saw him as "kind of like the youngest of three boys -- that was how he grouped himself." Mulroney remembers "when I was 15, I was real short, I was very runty. I grew at the end of my junior year {in high school}, and I grew three-quarters of an inch when I was 21." He's 5-foot-9 3/4 now, but all three brothers and their father are taller.

Today, he said, "I think we're closer now that we're not living in the same house." One weekend this spring he visited Sean, a third-year law student at Loyola University in Chicago, to hear Sean's rock band (called Tic-Tah after the sound of a metronome). The next weekend he spent with Conor, a bartender and skier in Olympic Valley near Lake Tahoe. Keiran, graduating in June from Columbia University, "is a singer and an actor and is probably going to try for it, although he may stay in New York," said their mother. "He just had a lead in a play at Columbia." The youngest, Moira, finishes at T.C. Williams in June and professes no interest in show business.

After his sophomore year in high school, Mulroney spent a summer at the prestigious Interlochen music camp in Michigan but decided he did not want to become a professional musician. He also won many music competitions and studied with cellist Loren Stephenson of the National Syphony Orchestra. "By the time I was a junior or senior in high school, I was in six different orchestras -- all-city, chamber, youth orchestra ... At that point in my life, it was what I loved doing and what I did."

But he didn't pack his cello away when he went to college, and as an arts-and-sciences major at Northwestern University, "I took lessons for credit from a great cello teacher for two years and played in the symphony." In ABC's "Daddy," which aired in April, Mulroney portrays a teen father who is also a musician -- in the film, he plays both cello and guitar.

"Daddy" put both Mulroney and his co-star, Patricia Arquette, on the cover of People magazine, which used the show to illustrate an article about teen-age pregnancy. There was little about the young actors in the magazine, which was all right with Mulroney. "It's even better to be on the cover but not be in it," he said. "I want to try to ease into it, rather than splash."

His career seems to be "easing" rapidly, if not splashing. No sooner had he moved from Northwestern to Los Angeles and joined the stable of young actors managed by Barbara Gale than he got the lead in "Sin of Innocence" with Megan Follows, who had starred in PBS' Emmy-winning children's series, "Anne of Green Gables." (Follows' continuing portrayal of Anne in "Anne of Avonlea" debuts on The Disney Channel Tuesday.) The two played stepbrother and stepsister who become romantically entangled.

A radio-TV-film major at Northwestern, Mulroney had been involved more in in production classes than drama, but had performed in the school's popular "Mee-Ow Show," an annual review featuring a small cast doing improvisation with audience participation. He also appeared in Gilbert and Sulivan's operetta "The Mikado," although he later said that "I don't sing, exactly, I sort of shout in tune." At college, "I was making films and videos -- my friends' films and videos -- nothing serious, nothing full-scale. My first job, I think I was as prepared as I could have been ... I think I did have a head start."

Which may have been invaluable, since his only professional experience was a public service announcement for a Chicago high school encouraging teen-agers to remain in school, and an industrial film that he called "an anti-teen-alcoholism thing."

At Northwestern, "I conned my way into acting classes with a couple of lies and a couple of smiles. Barbara Gale put up a sign-up sheet and I did my thing, and I guess that's where my professional career got real." Gale, who went to Northwestern to speak to drama majors, was so impressed with his talent that she signed him immediately and snared his first professional acting job by simply asking the producer of "Sin": "Do you trust me?"

"He'll be a household name," said Gale, formerly a vice president at the William Morris Agency. "Everyone who's seen him says he's a better actor than Tom Cruise or Tom Hanks" or any of the current spate of young, boyish actors.

Soon after he finished "Sin of Innocence" he did a full-length film called "Survival Quest." "It's about an Outward-Bound type of program. I'm a student in that -- there are about six of us. In the first third of the movie, someone ets killed, and then we get involved with radical survivalists. I made that the end of last summer, then went straight the next day to make 'Long Gone,' and made 'Daddy' in January." By March he was working on an episode of the syndicated series "Fame," playing a dancer.

Blake Edwards cast him in a small role as Malcolm McDowell's profligate son in "Sunset," starring Bruce Willis as Tom Mix and James Garner as Wyatt Earp. "It's a movie about making westerns" said Mulroney. "It's a great little part -- it's just four scenes. I'm drunk in every one of them and drugged in some of them.

"I think people see something like that in me ... I think people see the bad side of me. It's poorly disguised, but it's in all of us. I'd love to get roles like the one Mickey Roarke plays in 'Blue Velvet.' All the parts I've played have had a bad side to them -- incest in 'Sin of Innocence'; I was a druggie in 'The Drug Knot' with David Thoma. In 'Daddy' and 'Long Gone,' I get my girl friend pregnant.

"I think I might even be better at comedy," he added.

Mulroney shares an apartment in West Los Angeles with two former Northwestern students, "one a writer who works for Lorimar, one a producer's assistant. They were both a year ahead of me at Northwestern." A couple who had been occupying the apartment's third bedroom moved out and Mulroney moved in. Matt Fox, who also caught Barbara Gale's eye at Northwestern, lives nearby.

"Most of my friends are involved in some way with the industry," he said in a March interview." If they're not acting, they're writing. Or working behind the scenes. We're all kind of in the same place right now, trying to make it."

So far, among the actors, Mulroney appears to be making it best. "I really haven't had any major hitches," he admits. "I'm so busy auditioning I can't tell you what else I've been doing lately." He took one short vacation, flying off to Venezuela for a week. "I have a college roommate who works down there for a lottery. He's filthy rich."

Dermot Mulroney's acting career probably began back in junior high school when he had the formidable role of the Stage Manager in Thornton Wilder's "Our Town." "The Washington Post reviewer from the Virginia Weekly reviewed it," said Ellen Mulroney, "and she loved Dermot. At that time he was 5 feet tall. He was very small. So he got a review when he was only in junior high. Dermot's always had this luck of the Irish."

According to his mother, he's always had a lot of self-confidence, too. "A lot of it came from music, putting himself out to be judged. He just doesn't get nervous. He's always been able to present himself as he is, and that's the best he can do. It sells well, Dermot's sense of himself. At some point I had an insight: The best thing you can do for your kids is to send them out feeling good about themselves."

Mulroney will be in town for his sister's graduation from T.C. Williams High School in June. Back home in Alexandria, he doesn't anticipate being mobbed by fans who see him as a rising star. "I don't think they'll notice me," he said. "It's such a big school and there are so many kids and they're all trying to get out and get to the beach. That's what I did."