Recession has shuffled Clay Jannon out of his life as a Web-design drone and serendipity coupled with sheer curiosity has landed him a new job working the night shift at Mr. Penumbra's 24-Hour Bookstore. And it doesn't take long for Clay to realize that the quiet, dusty book emporium is even more curious than the name suggests. There are only a few fanatically committed customers, but they never seem to actually buy anything, instead they simply borrow impossibly obscure volumes perched on dangerously high shelves, all according to some elaborate arrangement with the eccentric proprietor. The...