Science depends on the unexpected. Yet surprise and its role in the process of scientific knowledge-making has hitherto received little attention, let alone systematic investigation. This collection explores surprise as a historical category, as a staged performance or as a spontaneous reaction, or as part of a personal experience during scholarly endeavors. The texts are arranged in alphabetical order by author’s last name, and ranging, randomly, from “A Family Conversation” to “Zufallsfunde.” The arbitrariness of that order is meant to suggest the indefinite and surprising ramifications of human understanding. The volume is less a purely erudite collection than an epistemic and emotional exercise in friendship and gratitude, offered by members of Department II in honor of Lorraine Daston.