Bob Woodward peruses a well-thumbed manuscript, its blue paper cover threatening to tear away from the metal clasps precariously holding it together. Dated Sept. 25, 1974, the document is the second draft of William Goldman’s Oscar-winning screenplay for “All the President’s Men,” an adaptation of Woodward and Carl Bernstein’s book about their Washington Post investigation of Watergate. The burglary story that Woodward and Bernstein began to report during the summer of 1972 would, over the next two years, uncover widespread malfeasance and criminality within the Republican Party, send high-level White House aides to prison, prompt congressional investigations and impeachment proceedings and lead to the resignation of President Richard M. Nixon.

Sitting at a table in the sunroom of his Georgetown home, Woodward glances through Goldman’s 161-page script, recalling when “All the President’s Men’s” producer and star Robert Redford sent it to him for his input. With ballpoint pen in hand, Woodward had pored over the screenplay, scrawling “No!” or “Wrong” in the margins every few pages, usually where Goldman had inserted a made-up scenario or “His Girl Friday”-type banter for his and Bernstein’s characters to deliver.

“Goldman’s a jokester,” Woodward explains in his measured Midwestern cadence, referring to the motion pictures Goldman had already written for Redford, “Butch Cassidy and the Sundance Kid” and “The Great Waldo Pepper.” Alan J. Pakula, who directed “All the President’s Men,” would derisively dub Goldman’s original conception of the movie “Butch Woodward and the Sundance Bernstein” — a rakish picaresque featuring two intrepid reporters “loving and laughing their way through the East as they bring down the president of the United States.” The fact that the heroes would be played by Robert Redford and Dustin Hoffman, two of the era’s biggest movie stars, threatened to reduce the entire enterprise to little more than a slick, self-impressed buddy flick.

No movie springs perfectly formed from page to screen. But to read Woodward’s marked-up draft of Goldman’s screenplay is to realize that the “All the President’s Men” we know — the lean, flawlessly calibrated thriller that made millions at the box office when it came out in 1976, earned four Oscars and turned Woodward and Bernstein into legends; the movie that’s worshiped by reporters, political junkies and filmmakers alike; the movie that from the moment it opened seemed to fuse seamlessly with private memory and collective myth — that movie came perilously close to being forgettable, along, quite possibly, with Watergate itself.