Tatum's pal, singer Jennifer Young, says she never witnessed Ryan physically abuse Tatum, but she does recall an incident involving Tatum's brother Griffin. "We were all hanging out -- Leif (Garrett), Nicollette Sheridan and me, and next thing Ryan and Griffin get in a huge fight," Young, 37, recalls. "Ryan threw Griffin across the room and into the wall." On another occasion Ryan famously slugged the teen, knocking out two of his front teeth. "I was all over my dad when he did that stuff to my brother," says Tatum. "Griffin would lie about what had happened when he got beat up."

When Tatum was 17, she and Griffin moved into an apartment in Beverly Hills. In 1986 Griffin was driving the boat that claimed the life of Gian Carlo Coppola, the 22-year-old son of director Francis Ford Coppola. Don Crutchfield, an L.A. private investigator who worked for the O'Neal family, says, "It was a Hollywood family and a mess from the word go. Joanna was too busy scoring drugs to be a good mom. Ryan was busy with his career." Tatum, he says, "was the only sane one of the bunch."

O'Neal was still estranged from her father in 1984 when she met 25-year-old McEnroe at a Los Angeles party. Within two months the pair were living together. In May 1986 their son Kevin was born, and they wed three months later. "I loved him, but I also think going away with him was a great survival tactic," says O'Neal. "It got me away from my family."

Still, it was a difficult adjustment. "I thought Tatum was mature and equipped enough to deal with (parenthood)," McEnroe told PEOPLE in a May interview. "As I look back now, it was asking a lot for her at 22 years of age, given what she had been through." Just over a year after Kevin's arrival, their son Sean was born.

As McEnroe's ranking dropped from No. 1 to No. 20, O'Neal began itching to return to acting. Influenced by Madonna, who had befriended her -- "She said, 'You have got to get strong, girl.' I was very meek" -- she began working out with the singer's trainer and built confidence as well as muscles. But her growing independence created tension. "McEnroe was vehement about her not working," says O'Neal's friend Mengers. "When I used to call the house to talk to her, he'd grab the phone and say, 'You aren't to call here and talk about work.' " In his book McEnroe maintains that "her acting career had tailed off." What he "felt strongly about," he writes, "was that I never wanted both of us to be working at the same time."