The Da Vinci Code is well written and entertaining, but we must take it more seriously than a standard fiction book because the author claims it is accurately researched and based on factual information. If Brown had stated in the introduction of his book that his material was conjecture, fiction, and not meant to be factual, then we'd have no problem with it at all. But no such disclaimer exists. In his acknowledgment page at the beginning of the book, Brown says,
Brown's third novel featuring Robert Langdon, , was released on September 15, 2009. According to the publisher, on its first day the book sold over one million in hardcover and e-book versions in the US, the UK and Canada, prompting the printing of 600,000 hardcover copies in addition to the five million first printing. The story takes place in Washington D.C. over a period of 12 hours, and features the . Brown's promotional website states that puzzles hidden in the book jacket of , including two references to the sculpture at Headquarters in , give hints about the sequel. This repeats a theme from some of Brown's earlier work.