Responding to the tragedy of Sept. 11, Mayor Giuliani is in his finest hour; from there, it's a slow descent to irrelevance by way of a failed 2008 presidential campaign.

In Giuliani's final chapter, he finds himself the closest he's ever been to the White House as Donald Trump takes office; without the guardrails his friends and loved ones provided in the past, Giuliani becomes a darker influence than ever before.