My favorite part of this Langdon adventure is he doesn't immediately have all the answers. While loyalty and trust are always themes in Brown's novels, this one is unique in Langdon interacting with people he has no recollection meeting. His puzzle pieces consist primarily of what he's being told by those around him. The twist at the end is superb!
I still would not rank this one above Angels and Demons or The Da Vinci Code. However, it is a must read. Get it here: