Rudy Giuliani emerged from the smoke of 9/11 as the unquestioned hero of the day: America's Mayor, the father figure we could all rely on to be tough, to be wise, to do the right thing. In that uncertain time, it was a comfort to know that he was on the scene and in control, making the best of a dire situation.

But was he really?

Grand Illusion is the definitive report on Rudy Giuliani's role in 9/11--the true story of what happened that day and the first clear-eyed evaluation of Giuliani's role before, during, and after the disaster.

While the pictures of a...