When Marcia Clark failed to persuade a jury that OJ Simpson was guilty of murder, she fell from grace with a bump - less a legal eagle than a dead parrot. Today's the day she gets her own back.

Today is the day that Marcia Clark comes out of hibernation, returning to the public stage to reclaim her piece of the OJ Simpson pie. For nearly two years, the prosecutor in the Simpson case has kept mum on her leading, losing role in a murder prosecution she considered eminently winnable, suffering what she calls a "malaise". More practically, she was bound to silence by the terms of a $4.2m book contract. But on the day that Without a Doubt at last arrives in American bookshops, she launches a 12-city US tour with a heart-to-heart with Barbara Walters, the lisping diva of American television hostesses, an encounter that promises to deliver at least one startling revelation.

Marcia Clark is coming to the game late. Defence lawyer Johnnie Cochran beat her to it by several months with his own memoir of the Simpson case, Journey to Justice, a very expensive publishing flop. Virtually every bit player in the Simpson case has already gone into print. The expected highlight of Clark's session with Walters, therefore, is the revelation over four pages in the middle of the book that she was date-raped as a 17-year-old by an un-named European waiter. "This highly personal detail," Time magazine reviewer Elizabeth Gleick observed, "is sure to surface during the tearful interview, bob up again with Oprah, and then again ad nauseam."

No one much cares any more, one suspects, if Clark calls Judge Lance Ito a "dunderhead", and former OJ Simpson attorney Robert Shapiro a "lightweight". They are celebrities from last season's television show. Instead, to her other feminist qualifications, this self-made, smart, successful single mum has added another women's issue. "It was over in seconds. I felt dirty, worthless," she writes.

Marcia Clark came to the Simpson trial well prepared to be a national female role model, "the feisty prosecutor" as Ladies Home Journal called her, "with the short skirts and dancer's legs". She had worked her way through law school as a steak-house waitress, shrugged off two failed marriages and run up an unbroken string of 19 homicide convictions over 10 years. But while Marcia had a tough row to hoe, somehow it was and is hard to feel sorry for her. She undoubtedly suffered in the trial - an assertive woman exposed to the public eye day in and day out, who did not fit the traditional gender role model - but she was not likeable. The immediate comparison is with Hillary Clinton, a leading woman lawyer whose hairstyles also seemed to change with her mood. The "B-word" (for bitch) haunts Marcia Clark, one sympathetic woman lawyer observed. The day before opening arguments were to start she threw a birthday party for her five-year-old son and 17 of his friends, ever the devoted parent. But she sued her ex-husband for higher alimony payments to pay for extra baby-sitting while she worked, and, it was reported, claimed a higher clothing allowance.

In the trial, one never knew which Marcia one was getting. She was by turns silky and flinty, playful and schoolmarmish, but plainly never one to suffer fools gladly. She is fortyish and not especially attractive. Johnnie Cochran, with his instinct for a weak spot, called her "hysterical". Most important to the American psyche, Clark was not a winner. "The evidence will show," she promised the jury, "that on 12 June 1994, after a violent relationship in which the defendant beat her, humiliated and controlled her, after he took her youth, her freedom and her self respect ... Orenthal James Simpson took her very life." The evidence did indeed convince most Americans that Simpson killed his ex-wife Nicole and her friend Ronald Goldman - but not the jury.

If Clark's understanding of the jurors' minds was critically off-key, so too, it seems, is her understanding of the media market. If the book had arrived for its original publication date last autumn, before the $33.5m judgement against Simpson in a civil court pricked the outrage over his acquittal, she and it would have been a hot item. But in her speaking appearances to date - for each of which she collects a reported $20,000 fee - she has kept to the subject of domestic violence and had audience members complaining of being bored. Earlier this year, she was proposed as the host of a nightly television show, Ladylaw, focusing on women in law enforcement. The major networks declined to pick it up. "Many observers believe the Simpson aftermarket will be tapped out," Variety magazine noted.

For all the pain of a teenage rape, she is now in danger of becoming like a salesman trying to freshen up an old story. As a school graduation gift, the book relates, her parents sent her on a Jewish youth group tour through Europe. In an unnamed holiday resort, as she tells it, a waiter trapped her and forced her into sex. It appears she told nobody and buried the experience. But she describes the memory resurfacing 10 years later, as a young prosecutor, when she sat down with the victim of the first rape case she handled. She started to feel sick and feverish. She compares her experience to that of Nicole Brown Simpson's family, who failed to deal with the fact that their daughter and sister was a battered wife. "I knew how to minimise, boy did I ever," she writes. "Denial sometimes is the only comfort you can offer yourself. Because once you let yourself feel, the misery is endless."

Clark's first husband was a professional backgammon player, a gambler. The second was a computer programmer and former employee of the Church of Scientology. She told him she wanted a divorce on Christmas morning, 1993. As he tells it, they were driving to his parents' home with the kids in the back.

Their two sons were aged two and five when the Simpson case got under way. She launched the trial proper with the melodramatic description of a trail of blood left by Nicole Simpson's faithful dog, Kato. Her fellow lawyers' opinion of her trial performance runs from "workmanlike" to openly scathing. With the benefit of hindsight, Clark is faulted for hanging her case far too heavily on Simpson's motive, that the killing was the culmination of a pattern of spousal abuse. And she apparently made a gross error when she insisted, against the advice of her own jury consultants, that black women would be on her side. On the other hand, it is said, Simpson's status as an African American hero may have made the case unwinnable. Either way, she now says, OJ "ruined me ... I can't be a successful prosecutor any more".

Clark was criticised for her hairstyle and her clothes. When Judge Ito warned the jury to disregard the way attorneys were dressed, he was plainly responding to her skirts, not to defence lawyer Johnnie Cochran's loud ties. Tabloids published topless photographs. "I was a survivor," Clark writes. "I had surmounted my personal difficulties through acts that took considerable initiative and will. I was a lawyer - an intelligent and accomplished one, at that. I was a damned good mother. And everything admirable that I'd accomplished seemed threatened by this disturbing and unsolicited celebrity."

The Simpson trial still casts a pall over every leading legal case in America. In the much-publicised investigation into the killing of JonBenet Ramsay, a child beauty queen, police vow to avoid "another OJ". In the Oklahoma City bombing trial, the FBI are on their guard against charges of fudging blood evidence, while the judge issued an unprecedented blanket gag order on all participants in the trial to avoid an OJ-style circus. But this legacy is the product not of the prosecution's work, but of the defence, of a "mountain" of evidence against OJ Simpson that somehow shrank to a molehill. OJ is held up as the way not to run a criminal case. The hero of the Goldman and Brown families is not Marcia Clark but civil trial attorney Daniel Petrocelli, who ground into Simpson on the witness stand late last year and delivered the multi-million dollar verdict for unlawful death.

Clark's book, critics already complain, provides virtually no fresh news, and Viking Penguin reportedly cut their expected one million print run in half. Her fellow prosecutor Christopher Darden's In Contempt, a best- seller, has already provided the inside scoop on the prosecution. Robert Shapiro's The Search for Justice rapidly disappeared from sight. One more celebrity auteur has yet to try her hand: Simpson's model girlfriend, Paula Barbieri, recently signed a $3m book deal. Just possibly, Clark will offer one tickling titbit: whether she did have an affair with Darden, on whose arm she appeared at several post-Simpson parties. So far, she isn't telling. "The question is irrelevant," she writes. "Fact of the matter is, Chris Darden and I were closer than lovers. And unless you've been through what we've been through, you can't possibly know what that means"n