“I first met Dirk … in the late 70’s. He was an imposing figure. Handsome, charismatic, a wonderful dresser—red suits, turquoise slippers. He cut quite a figure. He’d sort of explode into a room, usually with one of the top models of the moment on his arm. … Dirk introduced me to the scene around Saturday Night Live—which was the coolest place to be if you were young in New York in the late 70’s. … There was this fantastic scene going on in New York around SNL, and the first of the clubs—Studio 54, then the Mudd Club and Danceteria and Area. It was more, well, not exactly innocent, but genuine. Hanging out at clubs wasn’t a profession, and the media took months or years—not minutes—to discover it. I thought Dirk might be the one to chronicle that scene in fiction. As to why he didn’t write fiction … for years—well, life got in the way.”

—Grove/Atlantic Inc. editor Morgan Entrekin, when asked about Dirk Wittenborn

On a Sunday morning in July, Dirk Wittenborn was sitting in the backyard of his rented cottage in East Hampton, smoking. The 55-year-old novelist and screenwriter was wearing a polo shirt, baggy shorts and croc shoes and gazing at the sunlit channel of water that leads from Three Mile Harbor and empties into Gardiner’s Bay, where people could be seen swimming and clamming and kayaking. His wife, Kirsten, was watching their 5-year-old daughter, Lilo, make a watercolor of a butterfly. An old Scotty dog was snoozing on the grass.

“When you’re a teenager,” Mr. Wittenborn said, “you can have a sexually charged love affair, and it can cast a shadow across your whole life, and you will compare every encounter to that. And because it’s the first time and it’s so new, there will be nothing quite as vivid as that. You’ll burn down the barn, you’ll climb out the window, you’ll jump two stories to see the object of your desire. You believe you are different with that narcissism of youth, and you’re thinking, ‘I have discovered this wondrous drug and it’s going to last forever.’”

He took a drag on his cigarette. He was talking about his novel Fierce People, which was made into a movie directed by Griffin Dunne and which is opening Sept. 7. The main character is a 16-year-old New York City kid named Finn, who hopes to spend the summer in Brazil with his father, whom he’s never met. Instead he gets busted for scoring cocaine for his mother—a sexy massage therapist who gives a great foot rub—and the two of them end up living in a cottage on the estate of one of his mom’s massage clients, a New Jersey WASP. The film stars Diane Lane and Donald Sutherland.

Mr. Wittenborn said the novel is “emotionally” autobiographical.

Lilo walked over and giggled. “Mommy and you and me are going to Grandma’s house!” she said, referring to Mr. Wittenborn’s sister, Gretchen, who is married to Jimmy Johnson, a painter, gentleman farmer and heir to the Johnson and Johnson pharmaceutical fortune. They own the cottage Mr. Wittenborn rents each summer; their own spread is 10 minutes away, with panoramic ocean views, next to the Maidstone Club. They are the parents of Jamie Johnson, director of the documentary Born Rich.

“Yeah, to aunt Gretchen’s house later,” he said. “But we’re going to talk some more, so I’ll see you in a bit. You guys are probably going to drive ahead.”

“Drive ahead? Mommy!”

She trotted off and her Dad lit another smoke.

He got on the subject of the “Paris Hilton phenomenon” and the “calculation” of it. He said he remembered “a savage kind of wildness” to his own young years. “There were a lot more originals in the 70’s,” he said. “You saw them in New York, even in the fringe, like Rollerina—remember her? That transvestite who would roller skate? There were just these oddities. They had no sense of fame. When I first came to New York, money wasn’t cool. Really. It didn’t get you to the head of the line at the velvet rope. And now it’s purchased, it’s packaged …

“When I was a teenager,” he continued, “our world was the future and it was a golden future—you didn’t think AIDs was going to happen, sex was like shaking hands. And you never thought we’d be in another war like this. You never thought we would do this to ourselves again. Something was crumbling, and you thought it was going to crumble with a finality to it, and there was going to be a fresh start—and of course that’s incredibly naïve. But that’s what a whole generation thought. I think it was Albert Brooks who said, ‘We had America by the throat in the 70’s and we let it go,’ you know, after Watergate, after Vietnam—we got rid of a president, for God’s sake! Now you go protest, you go to an antiwar march and everyone’s like me, no young people, everyone’s a fossil.”

Last year he and director Neil Burger (The Illusionist) co-wrote a script about soldiers in Iraq who go on convalescence leave and end up in Las Vegas; the resulting film, The Return, which stars Tim Robbins and Rachel McAdams, just finished shooting. Mr. Wittenborn said he was taking his recent success in stride.

“I’m over 50, you know,” he said. “You wonder where everyone over 50 goes in Hollywood, or over 40. Do they take them into the desert and put them into a pit, into a sulfur mine? Where do they all go?”

Lilo came over to say goodbye.

“Bye dahling, it’s so sad,” he said, squeezing her tight.

“No, it’s not!”

“Okay. Kiss.”

“Sometimes I give mommy a kiss on the eyes!”

DIRK WITTENBORN WAS BORN IN New Haven, Conn., the youngest child of academics from the Midwest. His father was a college psychology professor at Yale and then Rutgers University. Sarah Wittenborn was his research assistant. Dirk’s father was a handsome raconteur who loved to fly-fish and moved the family to Pottersville, N.J.

The WASP’s there became intrigued.

“My family made a nice little package of eccentricity, a little fresh blood,” he said. “We could entertain, my father could talk about drug research. Everyone has problems, and he was a problem solver about anxiety and depression. They sometimes had troubled relatives, and they’d ask his advice.”

Dirk’s sisters were 9 and 12 years older than he.

“I was very much raised by my sisters, Gretchen in particular,” he said. “I was in her care, or lack of care, but it was always a caring lack of care.”

He was a shy kid. At the all-boys Pingry School in Hillside, N.J., he became aware of class differences: his classmates had last names like Merck and Bristol. One kid, David Haig of Haig & Haig Scotch, gave each teachers a bottle of Scotch one Christmas.

“I was dropped by accident, really, into this world, where everybody had brand names, and people had planes,” Mr. Wittenborn said. “I’d go to this kid’s house and there would be a squash court in the house.”

He loved listening to the old-money WASP’s. “Rich people don’t like to tell you all the rules,” he said. “They like you to show up inappropriately dressed. I’d watch the cruelty. Nice to me. Very cruel to others.”

One afternoon when he was 16 or 17, he was hanging out with a girl and her mother appeared. “She said, `Mother’s Day and no one cares,’” he remembered. “Then she came out later and said, ‘The lambs are bleeding for their mother.’” She overdosed a few hours later. Dirk took her to the hospital and was traumatized by her tan lines. “I had to lift this mother and her nightgown came up, and it was like her crack was radioactive—it glowed, the bikini line. It was so grotesque. As a kid, that was a weird thing to have happen.”

Not everyone thought the Wittenborns were a breath of fresh air. “There were people who violently, adamantly, said, ‘Who are these people? They’re awful,’” said Mr. Wittenborn. “My dad was a college professor, so I was an academic—the closest thing to a Puerto Rican they had.”

He remembers hearing Jewish people being referred to, in code, as “Hawaiians.” “That has to be one of the most repellent expressions,” he said. “It’s just so you can say it in front of their faces and insult them.”

The character of Ogden Osborne—played by Mr. Sutherland in Fierce People—is based on old-timers Mr. Wittenborn knew as a teen. “They lived by different rules, they were kings, pashas,” he said. “It was the last generation of guys who were from that American aristocracy that was created sort of out of crime and gold miners, and blackmail—the robber baron group—and they were the sons who still worked.”

One of them was John Seward Johnson Sr., whose brother Robert Wood Johnson Jr. expanded the Johnson and Johnson pharmaceutical company they’d inherited in the 1920’s. Seward focused on racing yachts and young women, and lorded over an estate in Princeton, N.J. His second wife, Esther, was a nice lady who would have the Wittenborns over for lunch. She let Dirk choose foreign movies to screen. At some point Dirk’s sister Gretchen started dating Seward’s son Jimmy.

At 76, Seward, divorced from Esther, married Barbara “Basia” Piasecka, a 34-year-old Polish cook Esther had hired. Like the Liz character in Fierce People, Ms. Piasecka gave a great foot massage. After Seward Johnson’s death in 1983, she inherited $500 million. Mr. Johnson’s six children famously contested the will.

After a court battle in 1986, Basia had to shell out $180 million to the kids. Jimmy Johnson—who had married Dirk’s sister Gretchen in 1975—now had a net worth over $100 million.

Meanwhile Dirk’s other sister, Betsy, had married well, too: to Manhattan art dealer Robert Miller. Dirk would take the train to the city and go to loft parties, where he became part of a scene which included Richard Avedon, David Hockney and Henry Geldzahler.

At the University of Pennsylvania, he learned about the Yanomami Indians of the Amazon. “They would binge-eat and the women would hide meat inside their vaginas,” he said. “They were known as the ‘fierce people.’”

When he graduated, with dreams of being a writer, he found a studio apartment on East 88th Street for $100 a month, then scored a one-bedroom on the top floor of 1010 Fifth Avenue, with a view of the Metropolitan Museum. There was no buzzer, so when he was home he’d put a little flag out the window.

While trying to write novels, he got a job doing research for books on pyramids and Catherine the Great. His first novel, Eclipse, with a character based on David Hockney, came out in 1977 when he was 25.

He became friends with the Saturday Night Live crowd, including Susan Forristal, a model from Texas who was dating the show’s executive producer, Lorne Michaels.

“I heard about Dirk through an old boyfriend,” said Ms. Forristal. “He told me he’d met this great guy at a Titanic party—Dirk of course was the captain, so he came as a ghost, with his hair platinum blonde.”

He went on to appear on SNL, notably in a commercial parody in 1977, for a “perfume for one-night stands” called Hey You, in which Gilda Radner takes him home from a singles bar.

Mr. Wittenborn moved into a brownstone on East 16th Street and built a greenhouse on his terrace. “For a young guy, this was kind of elegant and very kind of fey, some turn-of-the-century fantasy of mine,” he said. He was dating a lingerie model named Patty at the time.

His second novel, Zoë, was published by Dutton in 1983. “It completely threw me,” said Ms. Forristal. “I’m the main character. He took my life and put Patty’s body and face on it. A lot of it was a girl coming from Texas, becoming a top model—my things that I told Dirk.”

The book had fans but didn’t catch fire. He wouldn’t publish another one for 20 years.

Living below Mr. Wittenborn was Michael O’Donoghue, the dark satirist for SNL. They shot a video together called Laser Broad 2000 at Jimmy Johnson’s farm in New Jersey and afterward there was a lot of lingerie lying around.

For a video segment called The Kitty Swim School, Mr. O’Donoghue enlisted Mr. Wittenborn to throw 26 cats into a swimming pool at the United Nations’ Plaza Hotel.

“Cats can swim,” Mr. Wittenborn said. “They just scratched me and sprayed me. A couple of them were Michael’s cats and they were so fat. … Well, Michael loved to be mean, and loved for people to be mean to him. I think that in my life, there was a cruelty. It was funny, but very cruel.”

In 1984 he attended Ms. Forristal’s wedding to Mr. Michaels in Amagansett.

“People still say it was their favorite wedding,” said Ms. Forristal (she and Mr. Michaels divorced in 1987.) “There were 300 people and it was in our back garden. After we said our vows, and we were walking down the aisle, Lorne later said what a frightening sight it was to see Belushi standing in his white suit at the end of the aisle with his arms open wide, waiting for Lorne’s bride. It was a rough night—poor John ended up passed out under the bushes, God knows how much sex went on in the dunes. It was wild. Jack and Angelica were there, and there was peach mescaline that people kept dipping their fingers into.”

Apparently Belushi roused himself from the bushes. As Mr. Wittenborn recalled, “John said to me, ‘Do you want a ride back, I’ve got a plane.’ And we got on the plane, and I knew we were in trouble because John kept telling me, ‘There’s an Indian squaw in the corner.’ Somehow we landed at Teterboro and a limousine picks us up and John says, ‘Let’s go to Odeon!’ And we get there and I say, ‘John, it’s closed.’ And the next thing you know he’s figured a way to get in. And he’s in the kitchen and he’s starting to cook. One of the guys calls up [Odeon owner] Keith McNally, and Keith says, ‘Let him cook whatever he wants.’”

“We didn’t have any responsibilities, and there were a lot of drugs around,” said Ms. Forristal. “We were all young and those were the cocaine days.”

“It was that feeling that the world was just an adventure,” said Mr. Wittenborn. “Sex was safe and cocaine wasn’t addictive. Every night was a party, it was just out in New York. It was terribly, terribly seductive.”

Mr. Wittenborn allowed himself to be seduced.

“Dirk was like catnip to the girls,” said Ms. Forristal. “Dirk always had beautiful girlfriends … one gorgeous model after another.”

“He’s always managed to find these ravishing tall women,” said Melissa Chassay, a London socialite. “I’ve always joked with him, it’s like the tall and beautiful tribe, all the girlfriends throughout his life that he’s presented to me.”

Mr. Wittenborn expanded his reach: partying with David Gilmour of Pink Floyd in Greece, barhopping in London with T. Rex singer Marc Bolan the night Bolan died in a car crash. He met Germaine Greer at a party on Sutton Place; she kept calling him “Duck.”

“I found myself in these situations,” he said. “There were phases and it was actually very distracting. I was seeing it all.”

“You’re looking at this guy and going, This is like an American Depardieu, what’s going on here?” said director Jim Signorelli, who met Mr. Wittenborn in 1978. “You’re thinking, He looks like Depardieu but he acts like Clouseau. … He had this look like, Who could say no to this guy?”

One night after the two men had dinner with Ford model Carol Perkins, at 2 a.m. they were walking her home and hoping she might ask one of them up. No dice.

“Dirk and I are walking down the street, like Tom Sawyer and Huck Finn going, ‘Oh, damn, we can’t get no watermelon,’” Mr. Signorelli said. “And a window opens up from the fourth floor, and this incredibly beautiful girl sticks her head out and screams, ‘Hey, Dirk!’ And she throws a pair of panties out the window, and we look up at her and she says, ‘Hey, Dirk, call me!’ I said, ‘Who the fuck is that?’ She’s, if anything, more beautiful than Carol. Dirk said, ‘Oh, that’s Janice Dickinson.’”

Mr. Wittenborn tried to curb the heavy partying but then Belushi would show up and play with the switchblade collection Mr. Wittenborn had started as a little kid.

“John loved to play with them!” Mr. Wittenborn said. “I’d be working on something and I remember once he was fucking around and he got one of the switchblades caught in his lip, and he’s going, `Uh, uh, uh,’ and I had to pull back the clasp. And I’d say, ‘You’re driving me crazy!’

“I knew that John was burning it at both ends, and he was lonely. In the middle of the night, I’d hear him calling outside my house,” he continued. “I remember saying to a girlfriend, ‘Just don’t say a word.’ You’d just lie in bed, and that’s when I knew it was sad.”

Actor-director Griffin Dunne remembers his first impression of Mr. Wittenborn, at a Hamptons cocktail party.

“A bright red blazer with white buck shoes and short pants—I thought, ‘Who the fuck is that?’” said Mr. Dunne. “He was a real character and spoke in anecdotes and struck me as very eccentric. It was a very different point in his life and I think all sorts of things were motivating him to speak so much, and he was really pretty out there. He was kind of wired. It was kind of a bull-in-a-china-shop kind of thing. There was a recklessness about him.”

“Dirk’s a complicated cat,” said the writer Harry Hurt. “He used to go around in these big sissy costumes—a red blazer with red shorts and Gucci shoes and no socks. He himself would say, ‘This is my big sissy outfit.’ So he’s doing all that stuff but he’s mocking himself at the same time.”

Mr. Wittenborn took off, roamed around Brazil and Indonesia, wanting to be a real adventurer. “My parents were such hard-working souls, focused, and they didn’t take risks,” he said. “And I found that kind of paralyzing, and I didn’t want to live a fearful life.”

Overseas he became ill; he flew back and went to a clinic on the Upper East Side that Richard Avedon recommended. The doctor said he had amoebic dysentery.

Months later, he still felt bad. “There’s something wrong with me, I’m not feeling great, but I’m living a sort of great life,” he said. “I’m feeling really bad, late 70’s, early 80’s, and I had work to do, but I just have no energy, so I’m taking cocaine homeopathically to work.”

He moved to Los Angeles to try screenwriting, and got married for a few months; it didn’t work out. Soon he had enough of being “the lowest thing on the totem pole” and wanted to get back to New York where “eccentricity is valued.”

“Dirk had been in California,” said Ms. Forristal. “And back in Amagansett, we’d all spend a lot of time on the beach, on the tennis court, and Dirk was always very active—he was very fit. But now he looked like this old guy. He had this beautiful head—but his body didn’t look quite right. And I kept saying, ‘Why do you look so strange, your chest and your stomach—something looks wrong.’”

A doctor sent him for an MRI.

“And he says, ‘I’m going to walk you there,’” Mr. Wittenborn said. “And I said, ‘You act like I’m going to die.’ And he sits down, and he has a tear in his eye, and he says, ‘I don’t know how to tell you this, but you very well might.’ He thought I had liver cancer. It turns out I had caught a virus that calcified the sac around my heart. It was the thickness of two plastic playing cards. It really turned my heart to stone.”

He was told he had a one-in-three chance of dying.

“My reaction was, ‘I knew my wife would catch up to me.’ I thought, ‘Now I have really paid for my sins. I’ve paid for destroying my career and being irresponsible.’ It was a real eye-opener—I go, I have to change.”

He was in the hospital for a week. Doctors put catheters into the ventricle of his heart and then took snips off to test it. They couldn’t give him anesthesia for his heart because it would stop beating. “So they say, ‘Just lie perfectly still or you will bleed to death.’… You feel like you’re being invaded and abused and this changes you. I thought, ‘I have to change my path, I have to be nice to people.’”

The operation itself was brutal. “They did things to me out of the Spanish Inquisition. They peeled my heart like an orange and removed the sac—they sort of pull it out a bit, toss it around the room, and then they sew you up. Anyway I survived and it was like a youth tonic.”

Not at first though. He was “very, very sick.” His sister Gretchen brought him to her house in East Hampton.

“I felt so different,” he said, “and there was this shame and embarrassment of having been so self-destructive and blowing those years on being a drug fiend, and people were very cool about it, I have to say.

“He was just cadaverous,” said Ms. Forristal. “He was completely bent over, almost concave; it just hurt to look at him.”

“Having this heart operation was the best thing that ever could have happened to me,” he said. “I couldn’t have had the last 15 years if I hadn’t gone through that. The most comical part of it is everyone said, ‘Oh, Dirk’s burned out, he’ll never write again.’ People who were just so fed up with me, they’d say something, and people would go, ‘He almost died. How can you say that?’ So, suddenly, I got kind of a second chance.”

In 1991 Mr. Wittenborn went to a party at a Russian playboy’s apartment in Trump Tower. It was a midweek afternoon in August and there were pots of caviar. The Russian guys had bodyguards with ankle holsters.

He approached Kirsten Stoldt, a model and actress from Germany. (“I just chatted away,” says Kirsten, “and thought, ‘Oh, he’s just a good-looking gay guy.”) He asked her out. She stood him up; he asked again. In a taxi after the date Mr. Wittenborn made his move. “You must be kidding,” she said. “I thought you were gay.”

Three months later they moved in together and almost became collaborators.

“Because I was acting,” Kirsten said, “he said, ‘Why don’t you do a one-woman show about Eva Braun?’ I thought, What a brilliant idea. So we went to Washington, as part of our courtship, to do this research on Hitler and Eva Braun. And it was the most bizarre thing, it was getting me in touch with issues about being German, and so that was kind of a weird romantic thing. We stayed at the Hay-Adams in Washington and went to the National Archives and watched home movies of Hitler and Eva Braun. We got our own private room.”

They got married in 1997 at Jimmy and Gretchen Johnson’s beach house, in front of a birdbath. They currently live in Brooklyn Heights.

Kirsten’s water broke on 9/11. Their doctor was out of town; a resident psychiatrist helped to deliver the baby. “And he says, ‘You know, I’ve never done this.’ ‘What?’ ‘Well, I’ve seen it in films of women having babies, but this is actually the first time.’

“So they give me my daughter, and she’s crying; they hand her to me, and I say, ‘You know, maybe I can do this.’ It was wondrous.”

Kirsten gave up acting for a Ph.D. in psychology. “Being married to a psychologist is like, you know, in-house care,” Mr. Wittenborn said. “My wife has a moral compass that is so innate. She has a wisdom about things. My life has been pretty magical since I met Kirsten.”

In 2002 he published Fierce People. It hadn’t been an easy birth.

“I think he really did have a serious writer’s block,” said Kristen. “He was doing script jobs and other things in between; he kept going back to the book and being frustrated. The book dragged itself over three or four apartments and different stages of our lives.”

Griffin Dunne read the manuscript. “It was a book I knew I would love from the third paragraph,” he said. “What impressed me was how long this story had been sitting inside him, and how he was writing himself out of the grave.”

The novel got mixed reviews here but went through five printings in England, where he appeared nude in Tatler magazine.

This June, the movie version was screened in Southampton to an audience that included Howard Stern, Jay McInerney, Kelsey Grammer, Heather Graham and members of the Johnson and Johnson clan. Mr. Wittenborn recently sold his next novel, Pharmacon, to Viking Press. It’s based partly on his parents’ drug research. “It’s about the kind of optimism of the 50’s and 60’s,” Mr. Wittenborn said. “It’s about prescribing happiness.”

He says he’s living the quiet life; no drugs, just wine and cigarettes. “You know, I still go out,” he said. “But there was a little bit of that feeling of wanting to close the wagons. Having a child always changes you, especially for someone who stretched their adolescence for as long as I did, past 40.”

Some cranes flew overhead in East Hampton. It was time to go to Aunt Gretchen’s. After lunch, Mr. Wittenborn said he planned to jump in the ocean, play a little tennis, then drive back home “like a good bourgeois New Yorker.”