This is the story of an actor, two actors really, and how an obsessive devotion to craft and an unusual marriage and a prickly sense of fun can turn a bit part into a joy.

First be warned. You may not understand all that follows if you have never seen the television series "St. Elsewhere" (airing tonight at 10 on Channel 4) or heard of the voice of the car computer on "Knight Rider," or seen "The Graduate" or "1776" or "Two for the Road" or "A Thousand Clowns" or "The President's Analyst" or "The Parallax View" or "The One and Only" or "Oh, God" or "Reds" or the original off-Broadway production of Edward Albee's "The Zoo Story" or the dozens of other performances that stretch back 53 years in the life of a short, mustachioed, New England-accented 58-year-old actor named William Daniels.

Many who have seen him will struggle to remember his name, even after his latest flash of notoriety. But there is no easy way to wipe from the memory the spark of those performances. His characters are men we have all met somewhere, the demanding martinet, the driven achiever, the bumbling father, yet each with a dimension, a lightly scented whiff of humanity and humor that rescues the part from caricature and forces attention.

William Daniels' devotees are a secret cult, much fortified now by their hero's surprising acquisition of the Emmy for best leading actor in a drama series. Once they hear the full story of that Emmy night, not just the short, sanitized version Daniels gave during his acceptance speech, they can put aside any suspicion that the man and his characters -- particularly the redoubtable Dr. Mark Craig of "St. Elsewhere" -- might have no real connection, that it might be all actors' tricks. In the process, they will also learn much of the remarkable actress Bonnie Bartlett, who plays Ellen Craig, the surgeon's wife, and is married to William Daniels.

He had put on the tuxedo and even knotted the tie all by himself, but he wasn't happy. He was very good at being unhappy: "First of all, this is the third year I'm going over there not to get an award, right? We've got a show named 'Miami Vice' that's taken 16 nominations. They've got this young man in these slim suits that everybody is going out to buy, the clothes that he wears, and that's the way show business works . . .

"Now they send me this crummy limousine, that doesn't get one mile on the freeway and it breaks down . . . Here Bonnie is all coiffed, made-up, in this thing, high heels, and I said, 'I'm getting out . . . You want to come?' She said, 'No, I can't, my high heels.' I said, 'I'm going!' And I'm yelling, and I'm thinking to myself, they sent me a rotten limousine, Don Johnson's going to beat me, you know, it's just an El Dorado. It's not a real stretch. I mean, Don Johnson has the real stretch, probably in white."

The first thing people notice about Daniels is the precise, somewhat Boston-flavored diction, which is why he calls himself "a fabrication." He was born and raised in Brooklyn. His 81-year-old father, who lives with his 81-year-old mother now not far from Daniels' Studio City home, is a retired bricklayer who still speaks with "dees, dose and dem." His mother Irene was a stage mother to the 10th power, a telephone operator with almost no dramatic training who drilled her son and two daughters into a successful song-and-dance team by the time they reached grade school. That set the stage for Daniels winning a part in the long-running Broadway play "Life With Father."

He was 15, a bright boy who to this day wonders why he accepted his mother's obsession so gracefully. His juvenile parts on "Life With Father" required a Bostonian accent, so he removed every trace of Brooklynese. The transformation stuck, with only occasional lapses now around the house.

Turning 18 in 1945, Daniels was drafted and sent to Italy, where he served as an Army radio station disc jockey. Howard Lindsay, coauthor of "Life With Father" with Russel Crouse, had suggested Daniels use the GI Bill to attend a college with a good drama department. He talked his way into Northwestern, where his nonexistent academic skills would have soon caught up with him if he had not met Bonnie Bartlett.

She was the tall daughter of a Moline, Ill., businessman who quoted Shakespeare and passed on his passion for acting. She was a straight-A student, uncomfortable with boys, but her talent and voice caught the ear of the 20-year-old Daniels that freshman year when both tried out for a student production of Irwin Shaw's "Bury the Dead." Bartlett had already heard of Daniels as the New Yorker with "the phony English accent who had been on the Broadway stage."

When he introduced himself and invited her out for coffee, her first words were, "But you're too short for me." (Both of them, Daniels insists, are 5 feet, 7 1/2 inches.) Daniels persisted. Bartlett was secretly delighted to be approached by "a real actor" who wore a leather jacket. Daniels discovered that this girl was not only exciting and talented but could teach him how to pass exams. Although they would not marry for another four years, from that day in 1947 "we were practically inseparable," Bartlett said.

The Bartlett course in academic gamesmanship turned Daniels into a straight-A student, helped win him a graduate fellowship and made him reluctant to leave. Bartlett announced she was hungry to get to New York and had not arranged for the two of them to finish college in three years just to stay in Chicago. Daniels assented; they were off to Broadway.

Abandoning his wife, his limo and the sweating driver, Daniels discovered it was not easy to walk down an off ramp of the Ventura Freeway "in a tux, at 4 o'clock in the afternoon, and trying to look casual. I took my tie off and I thought to myself, maybe I'll look like Dean Martin, coming home from a late party."

Two women drove up and offered a lift, but Daniels said no, refusing even to look in their direction. They persisted: "Look, you happen to be one of our favorite actors, and you're dressed like you're going somewhere and you need a ride." Daniels relented. He thanked them, and after the short trip to his house was about to fetch his keys to rescue his wife when she and the driver pulled up in the sputtering limo.

"I'm going to go get another limo," the driver said. "Don't bother, I'm not going," Daniels said.

The first years back in New York were "tough, very tough," Daniels said. The producers he had known a decade before were out of the business. Often he had nothing to do all day but read The Times, the current best sellers, and listen to classical music.

His fiance', within a year his bride, attacked the theater world with her usual energy. "I worked, I took jobs. You know, you have to make money, and Bill didn't know how to do that . . . I worked for doctors . . . I worked for producers and in department stores. I would fit in three or four jobs a week, around my acting class."

She studied with Lee Strasberg. Daniels reluctantly signed up also. From the beginning Strasberg "thought she was terrific and he gave her free classes and made her the secretary of the class," said Daniels. "Me, he just had fights with."

It got worse when Bartlett won the role of Vanessa, "good and wonderful and perfect," in the television soap opera "Love of Life." Today, performing in a series in which her part is smaller than her husband's, Bartlett admits she does not like the fact that "he's the big mucky-muck, he gets all the good stuff." But when the tables were turned in New York in the '50s, "he couldn't take it at all. Forget it. . . . It was awful, just awful. His ego couldn't take it at all, no way."

One day she found him sitting in their apartment, reading the theater section of The Times. "Why don't you read the want ads?" she said. "Bonnie would say we've had three marriages," Daniels said. "At any point, it could have ended. There have been times when we'd just as soon have not been married. But I think basically that happens to a lot of people. They just don't happen to call a lawyer or file for divorce."

Said Bartlett, "The fact of the matter is, he's a lot of fun. Bill makes me laugh all the time. But there's a large part of him that's a child and that he's constantly dealing with."

The limo having been sent away, Daniels went back inside. "I took off all my clothes and put on a robe. There was a good tennis game on, a finals match, I turned that on. I'd been told by God that I was not meant to get to this thing, so I'm not going."

Bartlett persisted. She tried calling NBC. No answer. She suggested a cab. "CAB!" said Daniels, perhaps the only prime-time actor simultaneously drawing checks from two different series for two different parts. "Do you realize what a cab costs to Pasadena?" She suggested calling Daniels' sister Jackie, now an employment agency manager. "She has a Cadillac," Bartlett said.

In 1959, after a decade spent in brief television appearances and plays that usually died in infancy, Daniels won the part of Peter in Albee's one-act, two-actor play "The Zoo Story." Peter is the worried, inhibited middle-aged book publisher with a wife and two children. Albee's note says "he wears tweeds, smokes a pipe, carries horn-rimmed glasses."

Although mounted with a Samuel Beckett play that was supposed to draw more attention, the Albee piece became a hit. Daniels' success with his small but pivotal role began a chain of events that would influence nearly every important part he was subsequently offered, including "St. Elsewhere's" Dr. Craig. He won an Obie award and the Clarence Derwent Award. Suddenly, "there were playwrights who were thinking about me because they saw that performance."

He had stunned Albee by mining a vein of humor in the seemingly downcast part, which would be a Daniels trademark. As the schedule-tormented tourist in "Two for the Road," a movie that inspires nearly as many laughs from the Daniels cult as his "St. Elsewhere" character, Daniels resisted the blandishments of a director "who loathed the ugly American tourist" and who wanted him to play it to the hilt. Given his physical presence, his temperament, his accent and his success with "The Zoo Story," he accepted the fact he would play this part often. "My secret is, you don't play it. If you're a drunk, you don't play drunk. If you're a hard-ass, you look for every soft moment you can find . . . It's going to come out the way they want, because that's the way it's written. But if you play it the other way, then maybe you hopefully give it a little dimension."

By the mid-1960s, several directors had begun to realize what Daniels might do for them. Herb Gardner, who had seen "The Zoo Story," wrote the part of the social worker in "A Thousand Clowns" with Daniels in mind. Mike Nichols cast him as Dustin Hoffman's father in "The Graduate." He appeared in "On a Clear Day You Can See Forever" on Broadway and left the rehearsal of the Barbra Streisand movie for the part of John Adams in the Broadway musical "1776." From the prickly Adams he moved to the almost as prickly John Quincy Adams in the acclaimed television series "The Adams Chronicles."

He was no longer competing with his wife. Bartlett had left "Love of Life" to try other parts and motherhood. A child born while Daniels was doing "The Zoo Story" died within 24 hours. They decided to adopt two baby boys, Michael, now a 22-year-old UCLA graduate and opera student, and Robert, a 20-year-old fine arts student at Wesleyan University in Connecticut. Bartlett resumed her acting career when they moved to California in the 1970s. Before "St. Elsewhere," she had several television roles, including the widow Grace on the series "Little House on the Prairie" and the alcoholic mother on the after-school special "She Drinks a Little." But her children "were more fun than anything," Bartlett said. "I had no idea I would enjoy being a mother."

It was less fun handling the other juvenile in the family, the budding movie star whose perfectionist streak had also created some sensation off the screen. If, at a star-studded preview screening, Daniels discovered the director had snipped a favorite part of his performance, he would leave immediately. "I was a big walker-outer," he said. "I was a hothead. I mean, I walked out of all kinds of things that you wouldn't believe, things I was totally wrong about. I was enraged at what they cut out of my part in 'The Graduate.' I wouldn't even speak to Mike Nichols and whoever else was involved with that . . . It was just an alarming lack of maturity."

She was still wearing her new outfit and hairdo. "St. Elsewhere" had sent over a hairdresser and makeup man and she liked the results. Although the awards ceremony had begun in Pasadena, they were only a 20-minute drive away and it would be an hour before the show got to the place where Daniels might win an award. Yet her husband, the reluctant nominee, still sat in his bathrobe, watching a tennis match. She had been in analysis for many years and she knew how she felt about this.

"Bill," she said. "If we don't go, I am going to be so depressed, and I don't want to do that again. I have spent so many times buying a dress for an occasion, getting the makeup on, getting the hair on, getting all fixed for something and we don't go, or we walk out, because you're in a snit and you're in a foul mood, and I have to go out smiling at everybody, missing everything I was prepared to do . . . We walked out on 'The Graduate,' we walked out on the film of '1776' and you had to get drunk for six weeks after that . . . Goddam it, I just think you should at least be able to go there and sit through this thing."

Daniels agreed to let her call his sister and struggled back into his tuxedo, everything but the tie. "You know you have to be in a good mood for that. I had to use a clip-on."

At first, the producers of "St. Elsewhere" had something else in mind for the part of the chief of surgery. From conversations with other actors who tried out, Daniels gathered they first conceived "a real Italian type, inner city" for the inner-city hospital. But producer Bruce Paltrow knew Daniels; Paltrow's wife, Blythe Danner, had also been in "1776." Daniels knew of the series because Bartlett had earlier auditioned for the part of the head nurse, now played by Christina Pickles.

Finally, Paltrow called Daniels and said, "I have five scripts. I'll send them over. If you want to play Dr. Craig, it's yours." The scripts were clearly "superior to other television," Daniels said, but he could also see that "Craig wasn't that important . . . A lot of other actors said, 'Why are you taking this? It's so small.' "

A casting executive's suggestion that they use Bartlett to play his wife was eventually accepted, although Daniels still enjoys quoting a producer's first reaction: "No, she's too old for him."

On the set, "The first time I had to yell, they knew I knew what I was doing," Daniels said. "And then when I bumped into Ehrlich [the tall, bumbling young resident played by Ed Begley Jr.] and told him off, and he cowered or whatever, the writers said, 'We've got Mutt and Jeff here' and they started writing that. They loved it." The Dr. Craig character echoes the way William Daniels treats the young cast of St. Elsewhere. If someone blows a line, "I just say, 'Would you CONCENTRATE!!?' They love it."

Unlike a Broadway play, where roles retain their limits forever, the parts of both Craigs continue to expand in this season's early episodes, with the death of their son and their attempt to get custody of their new granddaughter. Bartlett confesses annoyance with the status consciousness that affects the way she and her husband are treated, but "at my age, in this business, you have got to be grateful for any kind of decent material." Daniels likes having her there: "I couldn't act the same way with somebody else . . . We're in the studio set kitchen, all right, what's to act? You put yourself in your own kitchen. And I am a little like he, and she is a little like her, although she's less like Mrs. Craig than I am like Mark." Bartlett agrees that her character "is less neurotic than I am" and she has had to work hard learning how to smoke.

As "St. Elsewhere" was beginning four years ago, Daniels was asked by producer Glenn Larson if he would read for the voice of a car in another series. With memories of the infamous failure "My Mother the Car," Daniels resisted, but Larson insisted it was a computer, not a car, talking, and coaxed Daniels into a small recording studio at Universal. They argued loudly over whether the computer should sound like a telephone recording, or the computer in "2001," or something else. But NBC liked the tape. Daniels' undercover life as the voice of KITT on "Knight Rider" had begun.

After a wrangle over money, Daniels signed on with the understanding he would get no billing, just in case the series was an embarrassment. It wasn't until strangers began to congratulate him on the series' success that he realized he had one of the most recognizable voices in the country, one that "St. Elsewhere's" success allowed many people to put a name to. When someone asked him after winning the Emmy if he was ashamed of doing "Knight Rider," Daniels defended it as a "nice, well-mounted show." In college, his wife recalled, "He was the poorest person I'd ever known, absolutely no money." Now two simultaneous series have, he said, "made me very well off."

The voice of television's raciest vehicle drives a blue Toyota Cressida to work, Daniels said, "but things are going so well, I'm looking at a Jag."

They arrived at the Pasadena Auditorium to find the Emmy ceremonies well under way. "They wouldn't let us in until the commercial, and I was seething," Daniels recalled. Finally they were rushed to their seats near the rest of the "St. Elsewhere" cast and production team. "Bonnie's chattering away with them all, you know, she loves to visit." Daniels sat and glowered, projecting enough gloom during one random camera close-up that producer Mark Tinker chided him gently.

"I was just there to make the appearance, right? . . . I would have bet $100, and I'm not a betting man, that Don Johnson would have gotten it. And when they mentioned my name, I couldn't believe it, just couldn't believe it. I had it all figured out. I pride myself on knowing how this business works."

He walked up to receive the statue, made his small speech alluding to the day he had had, then went backstage to be celebrated by the assembled media hordes. He spoke well, his tux looked fine, but he was uncharacteristically sheepish, what his wife calls "Mr. Nice Guy," when he finally returned to his seat in the audience near the end of the show.

"I owe you one," he said.

"Yeah," she said, "for about the next five years."