September release for Dan Brown's "Da Vinci Code" follow-up

Dan Brown

's follow-up to "The Da Vinci Code."

"The Lost Symbol" will be released Sept. 15, six years after "The Da Vinci Code" took the publishing world by storm.

The book, which had the working title "The Solomon Key," will follow symbologist Robert Langdon (

Tom Hanks

played him in the movie) during an action-packed 12-hour period.

Doubleday will publish the book with an initial print run of 5 million copies, the largest ever in Random House's history.

No other details to share, other than a promise from publisher Doubleday that the book will be set in an unexpected new landscape.

"Weaving five years of research into the story's 12-hour time frame was an exhilarating challenge," said Brown. "Robert Langdon's life clearly moves a lot faster than mine."

In the meantime, "Angels and Demons", the Da Vinci Code's prequel starring Hanks and directed by

Ron Howard