Everybody loves this book and I can certainly understand why. It has a very amicable 1P protagonist romping through a non-threatened, puzzle plot. It's not the Grand Cabal like The DiVinci Code beleaguered us with, and it definitely doesn't attempt metaphysical enlightenment like Eco's Foucault's Pendulum. I don't think author Carlos Ruis Zafon will be mentioned in this book's club readings.
A 20-something, over-educated kid lands a graveyard shift job as a bookstore clerk. He presents himself as an loopy entrepreneur, and he certainly has one of those inquisitive, tinkering minds that can't stop short of final solution on anything, except his unaccomplished life. His movie version will be played by Paul Rudd. The front of the bookstore has the usual, cursory genre works, but in the back, there's dusty, mysterious floor-to-ceiling bookshelves containing volumes of incommodious ciphers. No sentences, no illustrations, just gobbly-gook. When questioned, Penumbra is frustratingly vague and deliberately elusive, yet backhandedly bolstering his clerk's investigations. But it's when the clerk meets an alpha female rapidly putting rungs of the success ladder in Google's inventive hierarchy under her belt, well, then the fun really starts crackling. Ultimately it comes down to a confrontation of Old Knowledge against New Knowledge, with the bout ending up a split decision. No surprise there, and really, not a hell of a lot of wonder during the procedure, except for the literary assembly, of course.
All in all, a good entrainment, even if it does get a little whirled up in conclusion.