Publishers have taken extreme measures to protect the plot of "The Da Vinci Code" sequel from being leaked to the public ahead of its release, The Daily Telegraph reported Saturday.
"We have closed circuit TVs that are monitoring the books at all times in a secure area that is also guarded," said Random House spokeswoman Jacqueline Updike, whose company will publish "Symbol" in Britain.
"Symbol" is to be released in Britain and the United States on Tuesday.
The only detail of the new novel that publishers have parted with is that the action takes place in Washington during a single 12-hour period, the Telegraph said.
"This novel has been a strange and wonderful journey," Brown said on his Web site of his new novel featuring Harvard University symbologist Robert Langdon.
"Weaving five years of research into the story's 12-hour time frame was an exhilarating challenge. Robert Langdon's life clearly moves a lot faster than mine."