Mr. Penumbra’s 24 -Hour Bookstore, by Robin Sloan, is a quirky, modern fantasy/mystery set in the digital age. Sloan’s novel features books of clues to the wisdom of the ages and a curious cadre of young computer geniuses to unravel the mystery.
After losing his job during a downturn in the digital design field, Clay Jannon takes the night shift job at a 24-hour bookstore. He quickly determines that the store gets very little business but contains tall shelves of dusty old tomes that are borrowed but not purchased. Occasionally, a “new” one of these books arrives but he is cautioned against opening the books by the store’s manager, Mr. Penumbra. However, he is asked to make specific note of the person who borrows one of these books, down to their appearance, demeanor, and clothing. It doesn’t take long for him and a daring friend to start exploring the books, which they discover must be written in a type of code, and to determine that the borrowers are checking out the books in a specific order. Using his computer skills (and working with a new lady friend from Google), he is able to construct a face in the design of the bookshelves, following the pattern of borrowing. Things become stranger when Penumbra disappears to meet with a mysterious benefactor, and Clay and his friends follow and learn about the underground world of the “readers” and their life stories.
Mr. Penumbra’s 24-Hour Bookstore is an entertaining book with likable characters. Although the resolution may not be as satisfying as some readers might like, there are parallels between this group of “readers” and other secret societies driven to find meaning and preserve it for their members. Sloan also raises the philosophical issue of introducing artificial intelligence to solving mysteries that had been taxing to human bandwidth.
Mr. Penumbra’s 24-Hour Bookstore was published in 2012 by Farrar, Straus and Giroux.