I'm a little over 50 pages into Codex by Lev Grossman and I'm quite involved. There's a certain type of book that's few and far between... literary thrillers involving arcane texts, mysterious messengers and an immersion into diabolical goings-on that spin the main characters down mad pathways.

Past examples would be Eight by Katherine Neville, Foucault's Pendulum by Umberto Eco and The Club Dumas by Arturo Perez-Reverte. Dan Brown attempts to write these types of books, but despite his best efforts and recent popularity, doesn't quite succeed.

Anyways, I'm really digging Codex so far. I'll let ya know how it turns out...