Mr. Penumbra's 24-hour Bookstore

Robin Sloan's novel is a love letter to books, bookstores, and the pleasure of a good mystery — wrapped in a San Francisco tech-world that feels simultaneously warm and gently satirized. Clay Jannon's discovery that the nearly empty bookstore he works nights at is a front for an ancient secret society decoding a 15th-century printer's encrypted manuscript is exactly as delightful as it sounds. George Saunders called it "a real tour-de-force, a beautiful fable," and the ALA Alex Award, the Times Editor's Choice, and the NPR Best of 2012 nod are all well-earned. The caveat is mild: the Google-as-solution-to-everything plot engine feels more dated now than it did in 2012, and the ending is tidier than the mystery perhaps deserves. But as a warm, witty, completely clean read for book lovers and curious adults alike, it's one of the better light novels of the decade.