Foucault's Pendulum by Umberto Eco

This book centers around three editors for a vanity press in Milan. When the press decides to start publishing a series on the occult, the editors, up to their ears in conspiracy theories, decide to create their own version of the Plan, by which the Templars secretly went into hiding in the fourteenth century, and which they were supposed to use to return to power in 1944. But as the conspirators cook up the Plan, they realize that others are taking their game very seriously. Part of this book is a fun conspiracy story--it puts together an almost-plausible narrative that links the Templars with other mysterious groups through the ages (and has a ton of literary and cultural in-jokes, to book). What separates this book from something like The Da Vinci Code, though, is that the other part of the book is so moving. Belpo and Causabon, in particular, are well-developed characters, and the reader comes to understand that their manic devotion to finding the truth behind these conspiracy theories (which in the book are lined up like a house of cards) is about a lack of meaning in their day-to-day lives (which they only realize too late) rather than from any value inherent in the theories. I really enjoyed this story.