Mr. Penumbra's 24-Hour Bookstore by Robert Sloan

I saved this book for my vacation, and I couldn't wait to start it.  What booklover wouldn't love a book about a bookstore AND the cover said it was also a mystery.  So I loved it before I opened it up.  Yes, there is a mysterious kind of bookstore and there is a puzzle to solve, but the rest was a bit confusing and disappointing for me.  The main character, Clay, works the night shift at a bookstore in San Francisco where strange, quirky people come in to check out books that are written in code.  Clay uses all types of technology to eventually crack the code and figure out what's going on in the store and with the people involved.  Now I think I'm relatively tech-savvy, but some of the tech topics here were way beyond my understanding especially when's Clay's girlfriend (who works for Google) gets involved.  Did I like the book?  Kind of.  Would I recommend it?  Yes, to someone who is in their 20's and loves books.  I really think that's the target audience here and not old ladies like me.  - June