This chapter argues that the natural habitat of most books is not as solitary objects of contemplation and study, but as “social animals” on bookshelves, in store windows, and in the library. In seeking out this unfinished story about the character of books, we are led to consider their roles in human relationships. Turning to one of the most intimate moments in the ancient history of reading, where, in the opening of Cicero’s Topica, the author invites his friend Trebatius into his library, what unfolds is a story about the complex use of books in the negotiation of elite sociality at a moment of extreme political crisis following the death of Caesar. Like the best of books, Cicero’s text shows its reader what is unfinished about all of them: pointing her back to her fellow readers, to civic dialogue and learned friendship, and ultimately out of the library.