PositiveThe Boston Globe...worth a read for anyone who has wondered about the epochal changes wrought by the digital revolution — though it may come across as a bit unsatisfying to those who like their characters deeply and intricately portrayed ... Big societal questions vein the book, but never push themselves rudely to the forefront at the expense of the story ... In fact, everything here exists solely in service to the story. The writing in Mr. Penumbra\'s 24 Hour Bookstore\' is hip and amusing but make no mistake; this book is all about plot, not character ... Moreover, many of the characters suffer from a little cartoonish flatness, and sometimes seem mere levers to help move the plot along ... In the end, though, the book works fine as an engrossing mystery — and as an intelligent meditation on technology\'s trajectory and limits.