[A] document has surfaced in an unlikely place that sheds sorely needed light on Woodstein’s reporting while providing some perspective on the press’s role in uncovering the scandal.

Oddly enough, the document—a draft of a Woodstein story from January 1973—was buried deep within the papers of Alan J. Pakula, director of the eponymous 1976 Hollywood film based on Woodstein’s best-seller. Pakula, who died in 1998, deeded all his papers to the Margaret Herrick Library at the Academy of Motion Picture Arts and Sciences—the people who give you the Oscars. The collection includes his copious research for All the President’s Men, and in many respects, Pakula’s papers are more illuminating about the book and the movie than Woodward’s and Bernstein’s own papers, which are housed at the Harry Ransom Center in Austin, Texas.

The 15-page draft article is an unprecedented guide to how the Post’s reporting duo utilized the many anonymous sources they had painstakingly cultivated. For reasons unknown—Woodward and Bernstein have declined comment on this point—the reporters disclosed to Pakula the identities of some of these prized sources. The names are both scrawled in the corresponding margins of the draft and listed on a separate sheet of paper.

One of the six anonymous sources is the fabled Deep Throat, and he is no composite character, as skeptics have often alleged. Another is “Z,” that grand juror. Three of the four others are surprises. They include one of the three original prosecutors in the Watergate burglary, a onetime lawyer for the defendants, and a Republican operative whose name is probably unknown even to those steeped in Watergate lore. Taken together and put in context, these sources reveal not only the true anatomy of a Woodstein story but also an important truth about the reporting that won The Washington Post a Pulitzer Prize in 1973....

Why was Pakula, known in Hollywood as a perfectionist who researched his films deeply, so intrigued by this one article, out of the dozens written by Woodstein during the fall and winter of 1972-73? Why did Woodstein not only show the director the raw draft but share the identities of all but one of their confidential sources? Ironically, all this came to pass because the draft article was never published in the Post.

As recounted in All the President’s Men, the draft “produced the most serious disagreement between Bernstein and Woodward since they had begun working together seven months earlier.” No matter how many times Bernstein ran the story through his typewriter, Woodward expressed reservations, saying “he didn’t think it should run until they had better proof.”…

Their partnership—what J. Anthony Lukas later termed “a kind of journalistic centaur with an aristocratic Republican head and runty Jewish hindquarters”—never seemed closer to being ruptured. Bernstein accused Woodward of playing into the White House’s hands, while Woodward accused Bernstein of trying to push a story into the paper that might lead to another, even more damaging attack on the Post by Nixon Press Secretary Ron Ziegler. Woodward did not want to reprise that episode, especially after his talk with Katharine Graham over lunch.

Pakula was making a “buddy” film—the odd-couple nature of Woodstein was what had prompted actor Robert Redford to buy the screen rights—and the Hollywood director undoubtedly wanted to know why they had argued so bitterly in late January 1973. In retrospect, Watergate was on the verge of metastasizing into the biggest presidential scandal since Teapot Dome and, soon, the first effort to impeach a president in 100 years. So the Post reporters gave Pakula the kind of access normally reserved for newspaper editors only.