The Great Moment for Marvin Mitchelson usually begins around 10 or 11 at night, preferably a clear night when he can stand in front of the three floor-to-ceiling windows in his Century City law offices and contemplate the city at his feet: Lalaland, Gollywood, El Lay, the city where nothing is real and everything is possible. A divorce lawyer's paradise.

And it is splendid, you have to grant him that, from the headlights trickling like lava down the Hollywood hills to the pristine puddle of members-only darkness that is the Los Angeles Country Club, just across Santa Monica Boulevard.

At 54, with an income that sometimes goes over a million a year, Mitchelson can not only afford it, but afford to take this moment off to enjoy it. He is the first man to walk into an American court of law and claim that mistresses, i.e., one Michelle Triola Marvin, are entitled to what he calls "palimony" from their exes, i.e., one Lee Marvin, the actor. Mitchelson called this case "the worst setback for show business since John Wilkes Booth." And now comes Vicki "The Therapist" Morgan vs. the estate of Alfred "Marquis de Sade Complex" Bloomingdale. Okay, maybe Mitchelson didn't get a nickel in the Marvin case, and Vicki Morgan has fired him, but he has also represented big-bucks celebrity wives including: the ex-Mrs. Mick Jagger, ex-Mrs. James Mason, ex-Mrs. Marlon Brando, ex-Mrs. Bob Dylan, ex-Mrs. Rod Steiger, ex-Mrs. Van Johnson, ex-Mrs. Efrem Zimbalist, ex-Mrs. William Shatner, ex-Mrs. Richard Pryor, ex-Mrs. Groucho Marx, ex-Mrs. Alan Jay Lerner, ex-Mrs. Adnan Khashoggi, ex-Mrs. Eddie Fisher, and right now he's working for Sheika Dena Fassi, who wants $3 billion and an ex-rating from Sheik Mohamed Fassi, the guy who painted pubic hair on the statues around his mansion on Sunset Boulevard.

The Great Moment is about to begin. Mitchelson is alone and the phones have stopped clamoring, though certainly they can ring for him at any time of night.

"I have nightmares in which women are calling me, continually complaining about what their husbands and boyfriends are doing to them. I actually get these calls. I had a call in the middle of the night from Rhonda Fleming one time, she's saying, 'He took my bidet!' Her husband had come into the house and ripped the bidet out. I said to her, 'For the money we're going to get from him, we'll buy every bidet in Europe."

Anyhow, about this time of night, given a little peace and quiet: "I go into the bathroom and get into the Jacuzzi until I'm real relaxed," he says.

The bathroom, with its own view of Los Angeles, is just off the office, a sanctuary that Mitchelson's secretary keeps locked during Mitchelson's many absences: not only a marble scallop shell of a sink, but a matching black marble toilet with a stately look to it, but on which the seat is broken -- there are oddly shabby details like this in his life, like the cardboard box he keeps behind his Tiffany-glass desk, with an empty brandy bottle, old magazines, bank receipts and trash in it. The bathroom wallpaper is a crowd of misty-eyed houris with breasts like surgically implanted grapefruit halves. And at the back of the Jacuzzi, ready to cushion his harried, silver-gray head lies a pillow with a picture of his mother, Sonia, on it.

It's strange he'd choose her to relax on.

"When I was in law school," he'll recall, "if I went out at night, she'd meet me at the door when I got back and beat me with a broomstick and say, 'You can't come in, you should have been studying tonight!' "

Then again, his wife of 22 years, Marcella, has said that his mother's house "is the only place he can relax."

Mitchelson visits his mother every Sunday in Santa Monica, and "once in a while when I owe her some money she comes by the office." Mitchelson says this the way he says a lot of things, with a chuckle that's embarrassed and delighted at the same time. He is clearly a man who joyfully can shoulder the burdens of the stream of angry women in his life: "I love women," he'll say. "I am committed to their civil rights. I not only care about them, but if there's nothing in the law that provides for them, I want to create something that will provide for them."

So: the Jacuzzi, the pillow of Momma. He relaxes.

"Then I get out of the tub, dry off and put on this black robe," he says, rooting through the crowd of garments on a Victorian coat rack, on which hangs, too, an English barrister's robe. "I go back into the office, I dim the lights way down. It makes an interesting effect with the Botticelli Venus."

The Venus is in a big light box, inset in the ceiling. It's the famous Venus on the half-shell, except that Mitchelson has cropped it to show only her head, the hair flying, the wonderful frenzy of ultimately serene and unapproachable womanhood. His offices are filled with pictures of Renaissance, pre-Raphaelite and art nouveau maidens, angels and Venuses, in contrast to the furniture, which tends toward mammoth mahogany couches, armoires and breakfronts, huge masculine Victorian bulk which culminates, thematically, in the chair behind his desk, which is a red plush throne so high that he needs a footstool to rest his feet. On it he looms, all chuckles and empathy, over the office.

"Did I tell you about the chair?" he says. "It belonged to Rudolph Valentino." He says it cost "about $5,000, and that was 10, 12 years ago."

The thing about the light-box Venus in the ceiling is that when Mitchelson comes out in his black robe and dims the lights, "she reflects in the windows, she's floating over the city, she's so . . . ethereal. Do you know about her? She was the mistress of Botticelli and Michelangelo at the same time."

He sweeps his hands across the view to demonstrate how she'll float, his own personal angel, his command-performance anima.

"Then I put a symphony on the sound system and I get my baton, and I face that view and I conduct."

He conducts the third movement of Beethoven's Eroica, as likely as not.

"I like Beethoven. I like Mozart, too, the Jupiter symphony, but I guess the Eroica is my favorite."

The City of Angels prostrates itself at his feet. His own private angels hover above. He leads them through a maelstrom of romantic angst that pumps out of SAE speakers the size of small refrigerators.

He also has his own pair of wings. They are tiny and silver, pinned over his heart on the black robe. They're the kind that airlines give away as souvenirs to kids, these being from TWA. Stamped into them are the words: "Junior Crew Member."

Mitchelson was born in Detroit, the son of a Latvian housepainter, and younger brother to two sisters "who were always right, I wasn't allowed to argue with them. And more was expected of me than of them, I used to feel that."

When he was 18 months old the family moved to Los Angeles. His father ended up managing a string of apartment buildings, then died when Mitchelson was 18 and serving in the Navy as a medical corpsman.

After his two-year enlistment ran out, Mitchelson came home.

"I had to be the man of the family, I had to protect my mother. I wanted to be a football player, I even had a scholarship to play at the University of Oregon. My mother preferred me to be a student."

He stayed home and helped his mother run the apartment buildings while he went to UCLA, then Southwestern University Law School, a small local school.

His shingle had been hanging out for no more than two years when he started getting headlines, all preserved in scrapbooks, and "tons of boxes of media stuff stored away." Part of the price of fame is the clipping service that costs him $250 a month to add to the pile.

In 1958, he took on the case of a woman who'd driven into six parked cars, causing $25,000 in damages. He had her sue for $1,002,000, saying that one of the cars was parked too far from the curb. He got a settlement for her.

In 1958, he hit big ink by representing Mrs. Florence Aadland, mother of once-notorious Beverly Aadland, who as a young teen-ager was romantically involved with Errol Flynn. Mrs. Aadland was charged with contributing to the delinquency of Beverly. Ah, the headlines:

BEVERLY SOBS, SPURNS MOTHER IN COURTROOM.

He lost that one for Mrs. Aadland, who was quoted in one Los Angeles paper as saying: "Nobody is going to make love to my baby for less than $100."

After that, the scrapbook reads like an old movie montage, the headlines flashing one after another as Mitchelson ascends to fame.

LOVE LIFE TAPE MAY BE PLAYED, and MRS. MARX: HE'S A GROUCH, and "EDDIE EVEN THREW OUT MY BABY'S TOYS," and BRANDO UNFIT FATHER BECAUSE OF NUDE FILMS, EX-WIFE SAYS.

In the meantime, he was building a rep as a flashy young bachelor about town, his apartment full of zany objets like a bicycle hanging from his ceiling and an eight-foot-long shotgun, the kind of tacky-Bohemian image that counted for a lot in the L.A. of the 1950s. From the start, he was clearly not what's called a "downtown" lawyer in southern California, no probates and pin stripes for him, though he's quick to point out: "I've got a pin-stripe suit for when I need it in court."

He didn't hit the really "deep pockets," as divorce lawyers say, until 1964, when he marched into a courthouse with Mrs. James Mason and 40 witnesses, and settled the case before the gavel ever fell: PAMELA WINS DIVORCE, SPLITS MILLIONS.

"After that, I never had to look back," he says. Not that there weren't moments of pride for Mitchelson in Chapter One, The Early Years.

He got to the Supreme Court with a companion case to Gideon v. Wainwright, which established the rights of poor people to have counsel. In 1960 he also sued President Kennedy, for an accident caused by a limousine that Kennedy wasn't even riding in, and won $18,000.

"I still have the canceled check," he says now, sitting on the Valentino throne in blue Cardin suit, abstract splash-painted necktie and Dior shirt.

Wasn't the canceled check supposed to go back to Kennedy?

"Well, I have a copy of it."

He likes the grand gesture, the image of one man against a world full of titans, be they presidents or people ripping out Rhonda Fleming's bidet. He tried unsuccessfully to subpoena Richard Nixon in the $2.5 billion divorce suit against Adnan Khashoggi, the Saudi financier and arms agent. He recently traveled to the White House during the height of the publicity about Vicki Morgan and the late Alfred Bloomingdale, who was a friend of President Reagan.

"I wasn't exactly called there for coffee, that's all I can say," he says. (The aide who invited him was Morgan Mason, son of James Mason, whose millions Mitchelson had cloven in 1964.)

He has two Rolls-Royces, and Clark Gable's old custom-made convertible, and a Mercedes restored to look exactly like one belonging to a "Prince Rodrigue," who gave him a ride in Monte Carlo. (Mitchelson makes 15 or so trips to Europe every year.) He had a house perched so high on a mountain that mudslides didn't knock it down, they went out from under it, forcing him to take shelter in 5,000 square feet of a Beverly Hills house renting for $5,000 a month.

And the office: Persian rugs, knickknack shelves, a tree you could break your leg falling out of, and that view in back of the Valentino chair, three windows overlooking The Big Orange, which is beige just now--the smog is in.

He has a wife and son, he is saying. The son, Morgan, is 18.

He is not what you'd call a family man, even though he's been married for 22 years.

"I see my wife for a few minutes every morning, and sometimes at parties," he says. "She's blond -- she's rather attractive." She's Italian, he met her on Capri. She paints -- a one-woman show recently featured a picture of him on the couch at his mother's house in Santa Monica, with the title "Sleeping Barrister." Next to him is a copy of his book "Made in Heaven, Settled in Court."

She also once walked into a restaurant on Sunset Strip, grabbed the hairpiece of a woman Mitchelson was dining with, and dumped it in her fettuccine.

"That's not all she's done, but I'm not going to tell you about that," he says. The thought of her someday suing him for divorce is not a pleasant one: "That would be a Tylenol headache of the worst sort. Every lawyer in town would be out to get me."

The phone rings. His secretary has a client on the line. "Tell her I'm running late downtown," he says. Then he's back to the argument that Marvin Mitchelson doesn't bend the law but shapes it.

"I was with a probate lawyer this morning, a very conservative type who told me he's seeing many, many cases in which the Marvin case came up," Mitchelson says with that chronic mutter of a laugh. "He says, 'I settled one yesterday for $161,000.' Not all claims are successful. You have to face this when you're breaking new ground. They're resented by people who have strong religious and family beliefs against this."

"This" is the concept that women can be paid for being mistresses. Before the Marvin case, anything like it was thrown out as "meretricious," a suit which sought money for sex. Along comes Mitchelson. He says that sex has very little to do with being a mistress. In fact, the word "mistress" doesn't appear that often in Mitchelson suits, compared with "traveling companion," or "confidante" or, in the case of Vicki Morgan, "therapist."

"She gave [Bloomingdale] something very important to men -- quality and fabric of life. This is important. Sex is a very, very small part of it. These men are with these women all the time. Most of life isn't spent in the bedroom or on the floor or wherever you do it," he says, waving his hands as if a cloud of gnats were approaching him.

The phone rings. He answers it. He says: "I can't talk to you now, I'm taking a deposition."

Then he's back to the cause, the crusade for women's rights. "Let's say I need someone around me; I need my cup of tea; I need this and that. I need someone to listen to my confidences, and believe me, these men need that, and a woman gives up her job because I promise to take care of her . . ."

But didn't Sam Goldwyn once say that an oral contract isn't worth the paper it's written on?

"An oral contract is enforceable if you can prove its terms."

But if there's a job spelled out, aren't these women employes? Since when do employes get paychecks when the company dies? And right now, Mitchelson is breaking new ground, the six feet of it over the grave itself, with mistresses suing dead men's estates, with a homosexual suing his dead lover's estate, and a nurse in Illinois suing her dead patient's estate for alimony, palimony or whatever.

"You're using the word 'employe' in a very literal way, there," he says. "Let's face it, every marriage is a business relationship."

It goes around and around. He loves arguing this stuff. Yell at him. He smiles. He's happy. Press him and he launches into Victorian syntax.

"Please, sir, we have a sharp disagreement here," he says when asked about the case of the Harvard professor suing a man in California because he failed to impregnate her as she says he promised. "How can you say a woman isn't harmed by not having a child?"

Well then, how does he feel justified in bringing paternity suits, such as the one he's mounting against Spanish bullfighter El Cordobes?

Mitchelson has no shortage of answers, and he insists that women have a right to be paid -- if not for sex, then for that cup of tea, that listening ear.

"This is why I can take a Bloomingdale case despite my mother's raised eyebrows," he says.

The Eyebrows: Every Sunday, Mitchelson has to face them, rising like dirigibles on the face of his mother, Sonia of Santa Monica.

Things were going along fine with her son, the lawyer, until 1972 with the filing of the Marvin case. Mrs. Mitchelson could live with the newspaper articles about sex parties and hysterical women, and her son the madman interior decorator, but with the Marvin case, which went on for years, something changed.

Mitchelson's face folds into a fretfulness behind his amber-tinted glasses. He leans back on the Valentino throne, motionless for a moment under the three-windowed sky.

"My mother likes me," he says, "but it's very hard to earn her respect, she's a very hard taskmaster. Everytime I had an argument with my sisters, I'd be wrong. She'd say: 'Your sisters are industrious, you're not.' No, she doesn't approve of all my cases, and it started with Marvin. She doesn't like it, she doesn't like it. It's not my mother's way of life. She says, 'Marvin, you think you should be involved in something like that?' She always wanted me to be a judge."

They're hard, those Sundays, but it's always hard for Mitchelson, the women calling, complaining, crying, demanding. The advantage of being at his mother's house is that the calls don't come.

"She screens my calls. I can relax."

He can listen to her alone.

This is not to say that Mitchelson is entirely driven by the demands of women. In fact, it may be the men he's handled that he's really gone out on the limb for. He handled a Mickey Rooney child custody case. He went to Rome in 1969 to defend Raffale Minichiello, the U.S. Marine who hijacked a plane and took it to New York, Boston, Dublin and Rome. And Mitchelson went to New York, for almost no money (ordinarily he makes $200 a hour, or 15 to 30 percent of a judgment) to represent Ron Galella, the photographer who spent 11 years in and out of court for hounding Jackie Onassis and her children, tracking her on Greek islands, following her on Cape Cod with a motorboat, bursting out from behind a coat rack in a New York restaurant, camera flashing.

The judge said, "The Galellas of this world are two-bit chiselers and fixers." Which is to say that Galella lost.

"There was nobody else who would represent him," Mitchelson explains.

Still, this case means a lot to Mitchelson. It's another odd detail in his office, like the cardboard box full of trash, or the broken toilet seat: There are three framed pastels in his office, a triptych drawn during that trial. They have been left leaning against the floor-to-ceiling windows, despite a suite full of associates and secretaries who could help out with hammer and nails to hang them. They show Mitchelson, ferocious, haranguing a frightened Jackie Kennedy.

"I got pretty aggressive that afternoon," he recalls.

Mitchelson is the guy who has devoted the better part of his professional life to placating women, believing in them, fighting for them. How odd that he'd go all the way to New York and lose money for a chance at attacking a woman who is not only our national widow but the victim of a "two-bit chiseler." Isn't it enough for Mitchelson to amble out into the crepuscular magnificence of this office around 10 or 11 at night, put on the Eroica and wave away with his baton at his own personal angels, who never so much as raise their eyebrows?

Mitchelson: the man and his women.

The phone rings. It's Dena Fassi, she of the $3 billion divorce suit.

"I'll be right there, Dena," he says, and runs out.