One black, one white, one blond. Urban guerrillas dressed in flower-power garb, they were The Mod Squad, the hippest undercover cops on TV and the most watched trio in America from 1968-73. Millions tuned in to see the Afro cool of Clarence Williams III and the no-nonsense bravado of Michael Cole. But it was that girl—producer Aaron Spelling's very first blond—who really won their hearts. Waiflike and vulnerable with her long straight hair, Peggy Lipton was the sexy fulcrum of the force. She won a Golden Globe and was nominated for an Emmy four times in the five years she was on TV. She made an album and wrote a song ("L.A. Is My Lady") that Frank Sinatra later recorded. She was beautiful and famous and then, whoosh, she just disappeared. When the show went off the air she went with it, refusing to act full-time again. As the character she played, Julie Barnes, often did, Lipton vanished into the night.

Fifteen years later, she's resurfaced. After raising two children, losing her mother (with whom she was very close) and ending her 12-year marriage to record producer Quincy Jones, Lipton is ending her self-imposed exile. Now 39, she's making her comeback in an ABC movie, Addicted to His Love, airing Monday, March 28. As they used to say in The Mod Squad days, "Far out."

Her new home, purchased in January, makes it clear that her exile was not a painful one. The 14-room Bel Air, Calif, house looks like an Italian villa, white and spacious with huge pillars, lofty ceilings and doors opening onto an outside pool. Much of the furniture still hasn't arrived, but modern sculpture and antiques dot the rooms.

Why is she coming back? "Why not?" replies Lipton, looking quiet and serene. "I had a great marriage, but it's over, and acting is what I know best how to do. When I met Quincy in 1973, I was exhausted and burned-out from Mod Squad. He never said I should stop working, but there was never a doubt in my mind I was going to. I wanted children very badly, and I knew I couldn't do both well. This doesn't mean it would be that way for other mothers, but that's how it was for me. When the marriage ended in '86 [though the divorce isn't finalized], I thought, 'I can't just shop all day.' So I'm back into acting. My children support what I'm doing. My mother passed away in '86 [of lung cancer], but I talk to her all the time and she supports me too. She always wanted me to go back into acting, and now I'm doing it."

Yes, folks, we're in California. Raised in a Reform Jewish family, Lipton has long been interested in what's now called New Age spiritualism, and despite her practice of meditation, yoga and chatting with the departed, she insists she isn't a fanatic. "I'm kind of kooky," Lipton admits, "but do I look like a religious nut?" Her spiritualism, she says, has helped her overcome her greatest problem—painful, almost incapacitating insecurity. "I never had confidence, never," says Lipton. "The hardest thing to know is your own worth, and it took me years and years to find out what mine is."

The mystery of Peggy Lipton is why such a cool, elegant, fortunate, successful woman was so riddled by doubt. The daughter of Harold Lipton, a corporate lawyer, and Rita, an artist, she grew up in a comfortably upper-middle-class home in Lawrence, N.Y. Yet she was a nervous, withdrawn child, with a stutter so bad she sometimes couldn't even pronounce her name. "I didn't come from a background where I was hurt," says Lipton, who still has a trace of a stammer, "but I felt hurt inside. I was very guarded. I had a wall around me and a lot of fantasy locked inside."

"Peggy was always shy, more of an introvert than the others," says Harold, who now practices law in L.A. (Peggy's older brother, Robert, 43, an actor, also lives in L.A.; her younger brother, Kenneth, 38, is a businessman in New York.) "Maybe the influence of the household had something to do with that. She and her mother were both reserved, and in that case, the same apple fell from the tree."

If Peggy's interior was flawed, her exterior wasn't. At age 15, on the advice of a family friend, Lipton paid a visit to modeling maven Eileen Ford. "She took one look at me and said, 'Cut your hair, lose 10 lbs., get rid of your pimples and come back to me.' " Lipton quickly obliged, and three months later she was a Ford model. Because of her stammer she began taking acting classes, where she made a surprising discovery. "I didn't stutter when I was reading lines in a script," says Lipton. "When I got away from myself, I didn't have that problem." At age 18, Lipton went out on an audition for The Mod Squad. She got the role and became a symbol—for better or worse—of what TV and America were about in the waning '60s.

Lipton had her share of dates at the time, including Elvis Presley ("very sweet") and Paul McCartney ("very savvy"). She also lived with music producer Lou Adler, but her big love was Quincy Jones, now 55. Introduced to Peggy by his daughter Jolie, Quincy cooked lamb chops for her on their first date. Lipton, a vegetarian for five years, gave up her dietary beliefs that night. "I fell madly in love," she says. "I saw him cooking meat and thought, 'If I'm going to be with him, I'm going to have to change.' "

Married in 1974 (her first, his third), Lipton says she "loved being Mrs. Quincy Jones. It was like being a child and playing house in a way, until he got sick." Two aneurysms nearly killed Jones that year. Lipton remembers, "We were in bed reading, and just like that he went out, and his eyes rolled back in his head." After the second one a few weeks later, Jones was given a 50-50 chance to live. "That made me grow up real quick," says Lipton. "We were newlyweds and had a baby daughter. I was breast-feeding and had to go back home three or four times a day to nurse my baby. It made me very aware of how I felt about Quincy and how much I wanted him in this world."

Jones survived. So did the marriage. As a personal favor to Aaron Spelling, Lipton made a TV reunion movie, The Return of the Mod Squad, in 1979, but otherwise played the happy housewife at home. Until the mid-'80s. Long a respected musician and composer, Quincy became a megamedia light when he produced Michael Jackson's Thriller LP in 1982. "Our love never changed," says Lipton, "but Quincy's life changed after his success. The popularity made demands on his time and his life, and he had to change to meet them. Eventually it just wasn't working as a marriage anymore. It was a mutual decision based on a lot of things. By '86 he was doing his own thing, and I was doing mine. It was over." Being an interracial couple was never a problem for them or their families. "Quincy is about as nice a person as I've ever met, and he's a lovable man," says Lipton's father. "It's sad the marriage didn't work out."

Both Lipton and Jones are devoted to their daughters, Kidada, 14, and Rashida, 12. The children live with Peggy but spend much time at Quincy's house nearby. While Lipton returned to a vegetarian diet in the early '80s, she lets the kids eat meat. "I gave them a foundation for good nutrition," she says. "They can slip out of it, but if they get a zit, they know why. Otherwise they're both fabulous. If they're having troubles I talk with them. When they go to sleep, right before they go into that alpha quiet stage, I go in and brainwash them," she laughs. "They're superconfident kids. They have all the confidence I didn't have."

Lipton is winning small victories in her own battle for confidence. After the separation, she made a list of all the men she'd been in love with and kept looking at it to remember what her life had been. Although she says "there's definitely room for one more name," she recently threw the list away. "You can't walk around with that stuff from the past," she says. "The end of my marriage was sad, and I still love Quincy, but the way things are now is the way I want things to be."

Her energy, psychic and otherwise, is focused on acting. She plays a district attorney in Addicted to His Love, prosecuting a lothario (Barry Bostwick) who's conned four women out of money, cars, jewelry and trust. "Peggy was nervous when she first came on the set," says Polly Bergen, who plays one of the victims. "It's difficult coming back when you've been away so long. I know what it's like to give up a career for marriage and children and then try to come back all over again. Especially today, when the average age of a casting director seems to be about 12. It's tough out there, and she's courageous to do it."

Lipton is going at it full tilt. "I had a tremendous opportunity when I was young, and I worked my ass off," she says, "but I never had the commitment I have now. Back then I just kind of showed up. Now I mean it. In acting class I used to hide in the corner and pray the teacher wouldn't call on me. Now I beg to be picked. I used to worry I'd make a fool of myself, but I don't care what anyone thinks of me anymore. Really. I just can't wait to get out there."