This four-part documentary series presents the long, complex history of presidents testing the rule of law and the FBI's job to enforce it. It tells the story of the epic confrontations between the President and the FBI. From Nixon and Hoover to Trump and Comey, each battle illuminates a different facet of our democracy and the law. Using the present as a prism, we look back to see which lessons held up, which didn't and how the current investigation of the Trump administration might turn out.