I'm adding this one to my list of favorites. It's multi-layered in that it presents a classic detective novel with a basic whodunnit at its core. Add to that a layer of scholarly historical accuracy done with typical Eco flair. Then delve ever deeper in the labyrinth of religious and philosophical debate where the author himself appears occasionally, in discussions about semiotics. Unless you're a genius, you won't be able to read this in one sitting, and you won't be able to catch everything the first time through. I have to dogear pages, and underline passages. I'm sure I'll understand more of this when I'm thoroughly educated...for now I'll have to deal with the uncomfortable sensation that I'm not even as well educated as the poor novice...