This time, it's not a fanciful yarn about the holy father's deep dark secrets. Instead, the best-selling author of all-time, Dan Brown, takes aim at America's founding fathers and their connection to a mysterious fraternity with a secret handshake in his new book "The Lost Symbol."
The book was released this morning, and its plot has been a complete secret. About the only thing anyone really knew about it is that it's set in Washington, D.C., and that its opening scene takes place inside the imposing headquarters of the Scottish Rite Freemasons, one of the worldwide fraternity's bodies.
If the runaway success of Brown's books and movie "The Da Vinci Code" is any guide, the mysterious Freemasons are about to get a whole lot more attention.
"We don't know whether to batten down the hatches or throw open the doors and say, 'Come on in,'" said Brent Morris of Ellicott City, Md., a 33rd-degree grand commander of the Freemasons and author of the "The Complete Idiot's Guide to Freemasonry."
Ground zero for "The Lost Symbol" is the Washington Monument, the enormous shrine built to honor the nation's most revered Masonic president. For years, the common wisdom has been that the monument's granite stones include secret markings made by the Freemasons. And the monument to the nation's first president might not be the only landmark in Washington that's marked.
Conspiracy theorists have long maintained that the layout of Washington's streets includes Masonic symbols, such as the compass and the rule, and that the famous landmarks of Washington are really a secret code.
"[Freemasons] were very instrumental in the planning of the city," said Warren Getler, author of the book "Rebel Gold" and a consultant on the hit movie "National Treasure." "The theory that Dan Brown is going to put forward is that there is a geometric code, a Masonic code, in the layout of Washington, D.C."
The Freemasons insist that's an urban legend and that there is no secret code. But the Freemansons make perfect fodder for Brown, who is obsessed by secret symbols and powerful conspiracies. Among the members of the ancient Masonic fraternity are 14 presidents, Supreme Court justices, members of Congress, as well as countless other influential men.
Even before the book was released, entrepreneurs were hoping to cash in. "We think there's going to be a boom in tourism from people incredibly curious about the Masonic influence in America and in Washington," Getler said.
Getler is planning a three-hour Dan Brown walking tour of Washington, starting next month. "We think there's going to be a boom in tourism from people incredibly curious about the Masonic influence in America and in Washington, based on [the book], just like what happened in Europe with the Priory of Sion and the sites in France and ... Rome, and in Scotland at the Rosslyn Chapel."
Inside D.C.'s Masonic Headquarters
Washington's official convention and tourism arm, Destination D.C., launched a Web page to attract travelers to the nation's capital. The corporation teamed up with Brown's publisher, Doubleday, promoting the novel and travel to the city.
Grand commander Morris invited ABC News inside one of the pyramids that serves as the southern headquarters of the fraternity, where the organization's secret rituals take place. The walls are full of exotic symbols and there are even a few hidden passageways.
While showing off the Temple Room, where the Supreme Council meets and where Dan Brown's book begins, Morris admitted that the Mason fraternity makes for a great topic for conspiracy theorists.
"Yes, being an organization which has a history in the United States of almost 300 years, in Europe going back to written records of 1390, we're an old organization," he said. "People have always been curious about us. What are they doing behind closed doors? Why won't they let anyone into their meetings? And so wild speculation is out there about the Masons. And so what a wonderful plot device."
The Masons offer a tour of their headquarters Monday through Thursday from 10 a.m to 4 p.m., and they say thousands of visitors come through every year. Morris says he welcomes the attention, but he's not sure they can handle what is sure to be an increase in visitors to the headquarters.
"We're easily able to handle several thousand visitors a year, I don't know about tens of thousands of visitors per year," he said.
Some Freemasons are welcoming the attention that Brown's book is sure to bring to them, but they are also well aware that "The Da Vinci Code" was less than flattering to the Catholic Church.
It's unclear how Brown's book will portray the Masons, Morris said. "It could be a tremendous membership boost for us, it could be awful -- people could stay away in droves," he said. "We don't know, so we're going to just try to keep calm."