It's not just the movie industry that churns out unnecessary sequels-- apparently the book industry can get in on it too. Though technically Angels & Demons and The Da Vinci Code, from prolifically bland author Dan Brown, aren't just books anymore-- they're media empires, each with their own movie adaptation (Angels & Demons comes out May 15) and legions of fans to their name.

So it is with great inevitably that Brown announced today he would write a third book in the Robert Langdon series, to be called The Lost Symbol. And Sony, which owns all the rights to the Langdon character, will follow suit with a movie adaptation. Variety writes that the new book will be published on September 15, and given the three-year lapse between the Da Vinci and Angels & Demons movies, the movie version of Symbol will probably be a long time coming as well. Not that you will remember that this book exists at all once the hype has died down after its release-- unless the Vatican somehow finds a way to protest it again, that is .