The doomsday weapons in criminal trials are called tapes, recordings or some other tangible evidence. These are the ones investigators and prosecutors are most interested in. They are considered a winning card. Police and prosecutors sought to get such evidence from Shula Zaken, former Prime Minister Ehud Olmert's bureau chief, a month ago, when Zaken offered to serve as state witness. They didn't respond. The spirit of Olmert's former confidant was this: I am telling the truth about the firing, the obstruction of justice and the pressure on me, but I don't have anything to back me up or support this. Police investigators did not believe her version of events. Neither did representatives of the prosecution. If this was the case, they told Zaken's attorneys Ofer Bartal and Dov Gilad-Cohen, there was nothing to talk about. There would be no deal. Zaken did not understand why the lead prosecutors would give her up so easily. She did not understand that the prosecution was convinced that even without her it would get a conviction. She continued to pretend she did not have corroborating evidence, kept her distance from those who were not eager to strike a deal with her anyway, and contradicted herself the moment she understood what awaited her: a ringing conviction and long years in prison. So her lawyers returned to the negotiating table, Zaken was invited once again to the offices of the Israel Police Fraud Investigation Unit, and suddenly remembered that she had a tape. A tape? Explosive stuff, supposedly, grenades, amazing material that cast suspicion on the former prime minister for supporting perjury and attempts to obstruct justice, crimes that carry a maximum prison sentence of seven years. This is material that her family was keeping for a rainy day, and they have convinced her that the rainy day has arrived, that she will not have another chance to use it for her benefit. That it is time to get up from in front of the bulldozer she was figuratively blocking for Olmert and tell the police what really happened. This drama happened at the start of the week and led to a dramatic change in how the prosecution treated her. Senior officials in the legal system met in secret about the tape, examined the new evidence and the supporting material and understood that they could not ignore it. A prime minister allegedly supporting perjury? Allegedly obstructing justice time and time again? Only an insane person, a suicidal person, an irresponsible prosecutor, would dare bury a file like this -- and of course there are no prosecutors like this. There was a determined police force, a determined prosecution, and determined defense attorneys, who this time protected Zaken's interests and not Olmert's, and the deal went ahead. But Shula Zaken, who in these past years she has made every possible mistake, suddenly started listing new conditions and went back on her agreement to spend 11 months in prison. She had audacity and still has it. It happened Wednesday morning and in effect blew up the negotiations. The state prosecution was not fazed. "Don't want to? You don't have to," was the spirit of its response, and Zaken realized she would not be able to squeeze anything else out of it. The prosecution explained to her that the plea bargain must be reported urgently to Judge David Rozen and that there was no more room for dithering. She retreated, signed off, and probably breathed a sigh of relief. Everything is relative, of course, since she will be convicted of accepting bribes. In total, she will actually spend eight months in jail and she and a few others will have to testify in the scandal and once again know the long reach of Ehud Olmert and his posse. But this time it will be from the other side, since she has been marked as his new enemy.