How do we write a history of Christian missionaries in the late Ottoman Empire that takes human imperfection seriously? What do we learn about missionaries’ effects on the social fabric of the empire – by their actions and presence and the reactions to these – if we foreground emotion, contradiction, and misunderstanding? My paper seeks to explore these questions through the use of missionary records, memoirs, and Arabic journals and treatises. In particular, it utilizes the underused archival records and extensive correspondence of Alexander Watkins Terrell, the U.S. minister plenipotentiary in Istanbul from 1893-1897. Overall, the paper asks what it meant to try and live side-by-side. While older historiography has argued about nationalism, colonial resistance, or whether the missionaries were fundamentally imperialists, I argue for greater attention to the mutual conditionality of Ottoman-missionary interactions and the role of emotion. The largely American, Protestant missionary presence provoked a series of repeated policy and local responses from the Ottomans, which in turn elicited missionary replies. While social, foreign, political, cultural, and economic factors were important, emotions, especially wistful hopes, fear, anger, and frustration, played a profound role in shaping decisions and behavior. And while some interactions were certainly positive, the missionary presence within the Ottoman Empire grew increasingly problematic, especially during periods of social and political violence as in the 1860 Druze-Maronite conflict and the 1894-1896 Armenian terrors. Crucial to all of this was the mutual dependency of Ottoman-missionary behavior, each side giving greater significance to the other’s misdeeds than to good works and cooperation. Both sides had substantial and growing reservoirs throughout this period of real, plausible, and fictitious injustices to feed their fears and responses to each other. This in turn fed their responses, which tended to confirm their worst suspicions, thus having the opposite desired effect for the central Ottoman authorities of easing tensions and restoring social order. Certain regions fared better than others and the Ottomans continued to welcome aspects of missionary activity in education and medicine, but relations frayed more and more until 1914. While the 1850 creation of the Protestant millet had signaled a possible peaceful and stabilizing incorporation of Protestantism into Ottoman life, the subsequent events showed that the decisions and policies followed by the various parties, especially the Ottoman approach to religious liberty, undermined this prospect. Despite intentions, the Ottomans and missionaries both learned that a little tolerance, applied haphazardly, could be a terrible thing.