I finished The Rule of Four by Ian Caldwell and Dustin Thomason a while ago but forgot to hit the post button. Oops.

The quotes and reviews make this book out to be something like The DaVinci Code only more intelligent, but I think that is misleading. The Rule of Four isn't really a standard thriller at all. There is a historical mystery (based on a real mysterious book called the Hypnerotomachi Poliphili whose author has only been tentatively identified based on an acrostic in the text) but that, along with the Princeton campus, is really just part of the context of the book. It's really more a story of friendship and a classic "coming of age" story. Recommended, but not for people looking for thrillers like the DaVinci Code.