One of the pieces of Watergate trivia you learn if you read Bob Woodward's memoir The Secret Man is that the famous piece of advice given to the young Woodward by Deep Throat in the film version of All The President's Men, "follow the money," was an invention for the film that fooled Woodward himself.

For decades I had thought he used that precise phrase, but it is not in our book, All The President's Men, and I cannot find it in any of my notes. But that certainly was the idea.

So it's an accurate summary of the direction he was getting from Deep Throat, and for decades the phrase was attached to the man about whom almost nothing else was known. But it wasn't even something he said.

The night a couple years ago we all learned that Deep Throat was W. Mark Felt, a former Associate Director of the FBI, was exciting. This was a mystery (like the fate of DB Cooper and what happened to those guys who escaped from Alcatraz) I thought would never be definitively solved. In spite of the vows of Woodward, Carl Bernstein and Ben Bradlee that Deep Throat's identity would be revealed upon his death the secret had such an institutional quality, and even creepiness, about it that I just thought we'd never know.

Reading Woodward's book is still a total pleasure. My thought was that once we know Deep Throat's name and position it's all-downhill. Not true. Like any good story, it only gets better from there; the revelation of Deep Throat only leads to the long, fascinating origin story.

It's been popularly reported that revenge was Mark Felt's motivation for leaking to Woodward during his and Bernstein's Watergate reporting; that he was paying back President Nixon for passing him over for promotion to FBI Director after J. Edgar Hoover died. There's an element of that in the story, though it's hard to tell how much the revenge narrative is Felt's and how much is filled in by the reader. Certainly Felt was profoundly angry at the Nixon administration, but his anger was about much more than not getting promoted.

J. Edgar Hoover was the director of the FBI from 1924 until his death in 1972. His tenure lasted 48 years and outlasted 7 presidential administrations (Coolidge through Johnson). He had amassed an extraordinary amount of power in Washington, and as a result an extraordinary amount of independence for his agency. Mark Felt worked in the FBI for 30 of those years, becoming devoted to Hoover's vision and procedures and eventually becoming the second-in-command.

The Nixon administration wanted the FBI to make some changes. Some of them pretty reasonable: they wanted the FBI to adopt more progressive investigative techniques as well as hire women and minorities. Less nobly, they also wanted the FBI to do them some favors from time to time. For instance, there was one White House plan to use the FBI to (illegally) spy on what they felt were domestic security threats. Hoover fought the White House on this, though more as a matter of territory than principal (Hoover didn't exactly hold civil rights sacrosanct).

In another instance, a memo leaked to the media showing that a firm called ITT had paid the Republican Party $400,000 in return for a favorable anti-trust settlement. ITT claimed the memo was a forgery, though an FBI investigation authenticated it. John Dean pressured Hoover and Felt to change the FBI's findings to coincide with ITT's, but they wouldn't back down.

Hoover died at home May 2, 1972. This was about six weeks prior to the Watergate break-in.

Felt did write in his own memoir years ago that he thought he was well qualified to be the new director. Nixon, though, nominated not only an FBI outsider, but someone from the executive branch: Patrick Gray, a long-time Nixon associate who had been an assistant attorney general in the Justice Department. Aside from feeling slighted, Felt thought this was Nixon's attempt to gain control of the bureau for his own political purposes.

He was right. Less than a week after the break-in, Nixon would direct the CIA to interdict the FBI's investigation. The FBI narrowly focused their investigation on the break-in and bugging attempt, missing the larger, significant context for the Watergate operation. Moreover, they interviewed personnel from the Committee to Re-Elect the President (CREEP) in the presence of not just CREEP lawyers but sometimes John Dean himself.

This all infuriated Felt. The White House was compromising the FBI's integrity and autonomy, trashing Hoover's legacy of the bureau transcending temporary political power. What the FBI was powerless to do, though, Woodward and Bernstein could. Felt, as Deep Throat, would advise the duo in their reporting, keeping them on track and in view of the big picture. They were, essentially, acting as Felt's proxies.

Felt had been a deep background source of Woodward's, and someone Woodward had looked to for professional advice, sometimes to Felt's irritation, since they met by chance in 1970. It was sometime in July 1972 that Felt cut off all traceable contact with Woodward. No more phone calls, no more personal visits. From this point on, they would only communicate clandestinely.

He never told Woodward to "follow the money," though.