It was a plot device worthy of any film noir thriller. A shadowy figure, keeper of the secrets to a national crime, reveals snippets of information to the man struggling to crack the case. Meetings in shadowy parking garages... cryptic signals using flower pots on balconies... it was John Le Carre or Alfred Hitchcock at their best... And it was all true. Featuring interviews with Carl Bernstein, Bob Woodward, Walter Cronkite, Oliver Stone, Watergate prosecutor Richard Ben-Veniste and many others, this documentary examines the methods, motivations and far-reaching legacy of the man known as Deep Throat, now revealed to be W. Mark Felt, Deputy Director of the FBI during the Watergate era.