1. Related to the word “umbrella,” Mr. Penumbra’s last name can refer to an area of partial illumination (especially in astronomy) or something that serves as a shroud. What makes his bookstore a source of light, even though it operates in the shadows?
2. What were your initial theories about the bookstore’s mysterious patrons and their project? What did you predict Manutius’s message would be?
3. At the heart of the novel is the collision of old-world handwork and the automated digital age. How do Clay and Mat build a bridge between these two worlds?
4. Discuss Clay’s pursuit of love. What makes Kat attractive to him? What does it take to win her over?
5. The characters remind us that fifteenth-century technologies of the book—from punch-cutting to typesetting—were met with fear and resistance, as well as with entrepreneurial competition and the need to teach new skills. How does this compare to the launch of e-books? If you try to picture what literacy will look like five hundred years from now, what do you see?
6. If you were to file a codex vitae, capturing all you’ve learned throughout your life, what would it contain?
7. As Clay and the team of Google decoders take on the same challenge, what do they discover about the relative strengths of the human brain and technology?
8. Neel’s financial backing makes it possible for Clay to outwit Corvina and the Festina Lente Company, despite its many lucrative enterprises. In this novel, what can money buy, and what are the limitations of wealth?
9. Clay’s literary idol, Clark Moffat, was forced to make a choice between the Unbroken Spine project and his commercially successful fiction. If you had been Moffat, which path would you have chosen?
10. Are Penumbra and his colleagues motivated only by a quest for immortality? If not, what are the other rewards of their labor-intensive work? Can books give their authors immortality?
11. How did you react to Gerritszoon’s “message to eternity,” revealed in the closing passages? How can his wisdom apply to your life?
12. Discuss the physical traits of your copy of Mr. Penumbra’s 24-Hour Bookstore. Do you have a hard copy or an e-book, and where did you buy it? How does the design of the book enhance your reading experience?
13. Clay grapples with the fact that e-books could make brick-and-mortar bookstores unnecessary. How have your community’s bookstores fared in recent years? Did the novel reassure you about the role of technology in the lives of book lovers?