Adults 21+ are welcome to join us on the Back Porch for a beverage and a discussion of Mr. Penumbra's 24-Hour Bookstore by Robin Sloan. A gleeful and exhilarating tale of global conspiracy, complex code-breaking, high-tech data visualization, young love, rollicking adventure, and the secret to eternal life--mostly set in a hole-in-the-wall San Francisco bookstore. Registration required.