I somehow missed that this book was on the New York Times best seller list when it arrived in my mailbox as a gift from a friend. I read it because it is one of those delightful mysteries about books, with a big mysterious actual book at the center of the conundrum. As mystery books about books go, this one is great, but you sort of start to get used to the pattern. Person who is obsessed with the mystery of some odd old book. Archives are scoured for extra clues. A puzzle or two is discovered, then solved. A friendship hangs in the balance. There is some international travel. While I love all these ingreadients, and liked this book, it did represent a turning point for me -- the place where I started to recognize these sorts of smart literary mysteries as a genre, not as a few dissociated gems in the rough of mystery writing generally.

It’s good news, in my mind, that mysteries are getting more highbrow with books like The Da Vinci Code being both popular and thought provoking. On the other hand, the more authors learn that book like these sell, the more I am concerned that mystery-books-about-books will no longer just be written by passionate literary hobbyists -- as these authors seem to be -- but also by just any old mystery writer with a good research assistant. It’s a snob appeal thing and books like The Rule of Four make me very aware of my fear and concern that something that I enjoy will become popular and ruined. For now, books like this one, and Lev Grossman’s Codex and others by John Dunning, I can still feel are my little secret, NY Times best sellers list be damned.