Just finished this book from eReader. I got it to have something to read on the Palm on a trip to Santa Fe. It started out really good - a pretty decent clone of The DaVinci Code, but once the historical mystery got started, all the well-written narrative and dialogue, the good characters, and the likable romance just kind of got sabotaged by how amazingly arbitrary the mystery was. At every stage the answer to the riddle was an incredibly obscure, arbitrary one, that made no more sense than any of the other options. One of the good things about DaVinci Code is that the code, while difficult to decipher, actually made sense, if you had the right background. The code here, while it made sense, made no more sense than a dozen other interpretations, and yet our heroes unerringly nailed it, zipping from Rome to Alexandria to Avignon on the slenderest of clues, all of which a secret society supposedly laid down some 700 years ago. Also, the whole "bones" thing is a red herring. The story has nothing to do with bones, per se, at all.
This is the sort of story that would benefit greatly from being brutally cut down for a movie. The problem is that - and this is sort of a compliment - if the mystery were cleaned up, it'd be indistinguishable from DaVinci Code. Now is that bad for a movie this week? Hard to say - I haven't seen DVC yet.