NEW YORK (Reuters) - The hotly anticipated follow-up to author Dan Brown's "The Da Vinci Code" was released on Tuesday amid positive reaction from critics but the American novelist admitted he was under pressure to sell well.
"The Lost Symbol" comes six years after Brown's last book and again follows the adventures of Harvard professor Robert Langdon. It hit U.S. bookstores at midnight with an unusually large print run of 5 million copies and expectations the book can revive the publishing industry.
"There is plenty of pressure. You are following up 'The Da Vinci Code'," Brown, 45, told NBC's "Today" program in an interview that aired Tuesday. "You want to make sure that you hit it out of the park."
"The Da Vinci Code" sold 80 million copies worldwide, helped rejuvenate the book industry and was made into a film starring Tom Hanks that grossed more than $758 million, according to tracking firm Box Office Mojo.
The mystery-detective novel set in Europe caused a controversy and drew censure from the Vatican for its story lines about conspiracy and the Catholic Church.
In the "The Lost Symbol," Langdon becomes immersed in the secret world of Freemasons and their rituals taking place over 12 hours in a 600-page thriller set in Washington, D.C.
"The topic is so interesting and so mind-boggling and so complex that I needed a lot of extra time to research it and understand it to the point that I could work it into the story," Brown told "Today," explaining why it took six years.
The new book isn't expected to be as controversial as "The Da Vinci Code."
"It's hard to imagine anyone, after reading 'The Lost Symbol,' debating about Freemasonry in Washington, D.C., the way people did Brown's radical vision of Jesus and Mary Magdalene in 'Code'," the Los Angeles Times said in a review.
"That book hit a deep cultural nerve for obvious reasons; 'The Lost Symbol' is more like the experience on any roller coaster -- thrilling, entertaining and then it's over."
The New York Times said Brown had escaped the curse some other well-known authors had suffered when they followed up popular books with embarrassments.
"Mr. Brown hasn't done that," the newspaper said in its review. "Instead, he's bringing sexy back to a genre that had been left for dead."
The book is being released by divisions of Random House, a unit of German media group Bertelsmann AG.
Some critics have disparaged Brown's writing and the author acknowledged his style has not been universally praised.
"The Da Vinci code had the audacity to park at No. 1 for a little bit too long," he told Entertainment Weekly. "And it became very en vogue just to trash my books."
Editing by Danniel Trotta