Columnists, talking heads and op-ed writers are holding open auditions for a role that presumably needs to be filled if we are ever going to get to the bottom of what seems fated to be dubbed, for better or worse, Russiagate: a new Deep Throat.

I get it. In the years since Watergate, the Washington Post’s famous golden source—later revealed to be former FBI No. 2 executive W. Mark Felt—has become practically synonymous with the ideal of the noble leaker. The original Deep Throat “was instrumental in thwarting the conspiracy and bringing [President Richard] Nixon down,” Harry Litman, a former deputy assistant attorney general, approvingly wrote in the Los Angeles Times in May. “Was it wrong for Deep Throat, as FBI official Mark Felt was then known, to guide the investigation?” Washington Post columnist Margaret Sullivan asked in June, in the midst of a column praising leaks and anonymous sources, and inviting more. New York magazine columnist Frank Rich has gone a step further and already announced his casting choice: James Comey is today’s Deep Throat.

The unarticulated presumption, which Sullivan, Litman and Rich are not alone in making, is that Felt—the FBI’s deputy director in June 1972, and subsequently the parking-garage interlocutor who steered Bob Woodward and Carl Bernstein to reportorial heights—was an honorable, selfless whistleblower intent on exposing the lawlessness rampant in the Nixon White House. Or, as David Remnick spelled out in the New Yorker—echoing Deep Throat’s original hagiographers, Woodward and Bernstein—Felt “believed that the Nixon administration was corrupt, paranoid and trying to infringe on the independence of the bureau.” The president and his top aides ran, Felt believed, “a criminal operation out of the White House, and [Felt] risked everything to guide” the Post reporters. A new biopic about Felt, starring Liam Neeson, is due out on September 29 and shows every sign of continuing to portray Deep Throat as a profound patriot and dedicated FBI lifer.

But here’s a heretical thought: Mark Felt was no hero. Getting rid of Nixon was the last thing Felt ever wanted to accomplish; indeed, he was banking on Nixon’s continuation in office to achieve his one and only aim: to reach the top of the FBI pyramid and become director.Felt didn’t help the media for the good of the country, he used the media in service of his own ambition. Things just didn’t turn out anywhere close to the way he wanted.

Only recently, more than four decades after Nixon’s downfall, has it become possible to reconstruct Felt’s design and what really happened during those fateful six months following the Watergate break-in. Doing so requires burrowing through a great number of primary documents and government records against the backdrop of a vast secondary literature. Nixon’s surreptitious tape recordings rank first in importance, but only mark the starting point. One has to also research documents from the FBI’s vast Watergate investigation; the bureau’s subsequent internal leak investigation; records from the Watergate Special Prosecution Force; documents from Felt’s own FBI file; and lastly, two unintentionally rewarding books: Mark Felt’s original 1979 memoir, The FBI Pyramid, and the slightly reworked version published in 2006, A G-Man’s Life.

What you’ll end up with is the real story of Deep Throat. And you might be left with this realization: No matter what happens to Donald Trump—whether he’s absolved, exposed or neither—you should hope there’s nobody as duplicitous as Mark Felt manipulating our understanding of Russiagate. ...