He was many things - inspiration to a generation of investigative journalists, Judas Iscariot of the Nixon cabal, a shadowy figure whose very vagueness encapsulated an unsettling, confusing era.
In the end, though, "Deep Throat" remained a walking cipher, an icon with uncertain motivations who represented the most complicated parts of a time when nothing - not even the state of the American union - was exactly what it seemed.
One-time FBI official W. Mark Felt outed himself as Deep Throat 3½ years ago after three decades and an agonizing internal debate. To hear his friends tell it, he spent the end of his life relieved of the burden that he placed upon himself when he chose to covertly spill various beans about Richard Nixon's misdeeds.
Yet in a way, Mark Felt the man didn't matter as much to history as did his alter ego. Because the character he created, named after one of the first porn movies that reached into mainstream culture, was one America desperately needed at that moment: someone who would, with no visible rewards, blow the whistle on the yarn to end all political yarns.
He was also, for many Americans, an entry point into the murk that brought down Nixon's presidency.
"It's with the figure of Deep Throat that you feel like you come into contact with that kind of hidden secret infrastructure that is so much a part of the Watergate story," said Andreas Killen, author of "1973 Nervous Breakdown: Watergate, Warhol and the Birth of Post-Sixties America."
"He was somebody out of Central Casting," Killen said of Felt, who died Thursday in Santa Rosa, Calif. "If he hadn't been a real figure, and Hollywood wanted to make a movie about Watergate, they would have had to invent somebody like him." He calls Felt "almost heroic, almost virtuous, almost noble."
Deep Throat also was almost never unmasked, at least in his lifetime. Carl Bernstein didn't meet him until last month, and Bob Woodward kept the secret through nearly 30 years of speculation. Was it Alexander Haig, some people asked? Or Henry Kissinger? Or a combination of people - a "composite" used by the Washington Post reporters to personify important information?
It's difficult today, even for those who were around, to summon the full force of that moment in history when Deep Throat changed the country and the presidency. America was still reeling from the 1960s, a paroxysm of a decade that, among so many other things, had significantly diminished citizens' faith that their government would be on the side of the angels.
Two Kennedys and a King were dead, Lyndon Johnson had left office with his tail between his legs, and the war in Vietnam was mired in long-term uncertainty. The energy crisis was ascendant, terrorism was just starting to show its face, and suddenly the question on everybody's lips was: What did the president know, and when did he know it?
Into the mix came this political version of the Unknown Soldier, straight out of the John le Carre and Robert Ludlum Cold War spy novels so popular at the time. With him came signals via red flags, covert messages in newspapers and nighttime parking-garage powwows.
If the book by Woodward and Bernstein, "All the President's Men," didn't secure his place in the culture, then the 1976 movie version starring Robert Redford and Dustin Hoffman certainly did. In it, we see Hal Holbrook in the fabled parking garage whispering back-channel information to our intrepid reporters. It was unforgettable - and a pastiche that inspired thousands of young people to choose investigative journalism as a career out of the belief that, with the dogged pursuit of sources and the truth, some good could be done.
Some called Deep Throat a traitor. Some called him a hero. Woodward called him a secret, and that's exactly what made Felt's identity such an object of fascination over so many years. America likes nothing better than an unsolved mystery, and a conspiracy theory only makes it more mouthwatering.
"He became one of the great American mysteries. There's who killed JFK, is there a Bigfoot roaming around somewhere in the Pacific Northwest and is there a Deep Throat?" said Robert Thompson, a Syracuse University professor of television who studies how American popular culture works.
Thompson sees another crucial narrative element in the Deep Throat saga: He was a really serious player. In a story that unfolded with bumbles and boners, with botched burglaries and ham-handed lies and suspiciously absent segments of audiotape, this was someone with the goods. In other words, Watergate: created by idiots, revealed by experts.
"The whole thing looked like something out of a Mack Sennett comedy," Thompson says. "And suddenly you get this Deep Throat guy who looks like he's operating out of a serious spy thriller."
The allure of the mysterious insider whose motivations are unclear - but appear unexpectedly pure - endures. The popular TV show "The X-Files" told the story of another governmental conspiracy, this one dealing with extraterrestrials and the unexplained. William B. Davis played "the cigarette-smoking man" who would appear from the shadows and, in a husky voice, steer FBI Special Agent Fox Mulder off in another direction - usually the right one. The homage was obvious.
"People will debate for a long time whether I did the right thing by helping Woodward," Felt wrote in his 2006 memoir, "A G-Man's Life: The FBI, `Deep Throat' and the Struggle for Honor in Washington." "The bottom line is that we did get the whole truth out, and isn't that what the FBI is supposed to do?"
In 2005, when Felt said, "I'm the guy they used to call Deep Throat," he publicly came to terms with his own duality. Not so the rest of us. With his passing, the book of Mark Felt is shut after 95 years. But as with any good mystery story, the tale of Deep Throat echoes still.
(Copyright 2008 by The Associated Press. All Rights Reserved.)