This issue of Limn on "Ebola's Ecologies" examines how the 2014 Ebola outbreak has put the norms, practices, and institutional logics of global health into question, and examines the new assemblages that are being forged in its wake. The contributions focus on various domains of thought and practice that have been implicated in the current outbreak, posing questions such as: What has been learned about the ambitions and the limits of humanitarian medical response? What insights are emerging concerning the contemporary organization of global health security? To what extent have new models of biotechnical innovation been established in the midst of the crisis?