Foucault's Pendulum by Umberto Eco (Shane's book 15, 2010)

"Beware of faking, people will believe you." The power of fiction, the need to create and, most of all, to believe something are all key themes in Foucault's Pendulum, Eco's second novel. It's a kind of intellectual Da Vinci Code, one that piles conspiracy theory upon conspiracy theory but always with tongue in cheek.

[amtap book:isbn=0099287153]

The book opens with Casaubon, an Italian intellectual and publisher, hiding in a Paris museum at night waiting for a mysterious group who, he thinks, have kidnapped his colleague, Belbo. While he waits he considers the events leading to this point and we drift into flashback. Eco layers the flashbacks, creating a labyrinthine narrative with frequent digressions into the history of assorted medieval sects, the occult and extracts from Belbo's aborted attempts to write fiction.

Casaubon, Belbo and their colleague Diotallevi work for a small publishing house that deals with a lot of manuscripts from conspiracy theorists. They term these authors "the Diabolicals" and at first mock them. Later they have the idea of coming up with their own conspiracy theory, one that combines all of the crazy theories that cross their desks. What starts as an amusement eventually becomes something that they take more seriously and becomes dangerous once they realise that there are groups out there who believe that the trio really have uncovered a secret.

"Dan Brown is one of the characters in my novel," Eco told the New York Times in 2007. Life is too short to read books by Dan Brown so I can't speak from experience here but I'd guess that the difference between the two books is that Eco seeks to satirise and deconstruct conspiracy theories while Brown seeks to titillate. Eco fills pages with arcane references and history and after a while I stopped wonder what was true, what was legend and what he had invented. It doesn't matter - the content of the conspiracies is not the point of the book.

There is genuine tension in places and quite a lot of comedy but mostly this is an intellectual adventure concerned with the love of books and the pleasure of knowledge. It's also a pleasingly ironic exploration of worlds within worlds, reminiscent of Borges. It's a lengthy read but nowhere near as inaccessible as it might appear at the outset.