“Out of desperation, unemployed Clay Jannon takes the night clerk job at Mr. Penumbra's 24-hour bookstore. Only a handful of customers enter the story and they rarely buy books. They borrow the obscure titles that Clay locates and retrieves from Penumbra's dizzyingly tall bookshelves and then return them. Clay's convinced the store is a front for some other activity and enlists his friends' help to solve the puzzle, embarking them on an adventure that encompasses books, secret societies, science, faith, passion, the acquisition of knowledge, and possibly something much, much larger.
Robin Sloan's amusing novel combines past, present, and future technology and uses first-person narration to infuse an unusual (and rather unbelievable) plot with self-deprecating wit and wondrous appreciation of the amazing people in Clay's world.”