It’s been five years now since Dan Brown’s insanely popular The Da Vinci Code was published, and a lot of publishing industry types are getting antsy waiting for the follow-up, which is purported to be about freemasonry and America’s founding fathers.

From The Wall Street Journal:

The whole industry is impatient. Book sales are generally sluggish, and one explosive, high-profile title can jump-start sales across the board as customers pour into the stores and walk out with a bagful of titles. […] So where is the new novel? It’s a mystery worthy of the deepest secrets of the Knights Templar. Mr. Brown, holed up in New Hampshire, isn’t saying. His agent, Heide Lange, isn’t, either.

“When a major author doesn’t deliver, you get down on your knees and pray,” says Laurence Kirshbaum, a book agent who heads up LJK Literary Management in New York. “You can’t threaten, you can’t cajole, you wait.” Back in November 2004, a spokeswoman for Doubleday said the target publishing date for Mr. Brown’s next book was 2005, although she noted that “there are no guarantees.”

Now, the publisher is hinting that a manuscript is close. “Dan Brown has a very specific release date for the publication of his new book, and when the book is published, his readers will see why,” says Stephen Rubin, president of Bertelsmann’s Doubleday Broadway Publishing Group, whose Doubleday imprint publishes Mr. Brown. Mr. Rubin declined further comment.

From there, the Wall Street Journal reporter ties himself in knots trying to guess what the “very specific release date” will be. Could it be July 4th, perhaps? Or Oct. 13th, when the cornerstone of the White House was laid in 1792? Or maybe it’ll be Sept. 18, the same day that president Washington led a Masonic parade down Pennsylvania Avenue to lay the cornerstone of the Capitol Building in 1793?

For our money, the more pressing question is: how is Doubleday going to sell the film rights to this one, considering that the film has already been made under the title National Treasure?