There are powerful social, political, and epistemological reasons for concealing (or revealing) certain people and practices in the course of scientific research and publication. The human sciences—including biology and biomedicine as well as anthropology, linguistics, and social science—depend upon people with diverse values and expertise, who have varied motivations and degrees of political agency. Research encounters are often orchestrated by actors behind the scenes—tissue donors, survey respondents, student subjects, translators, activists, ethics review boards, civic or religious institutions, lawyers, nurses, and archivists. Their contributions move in and out of the shadows as scientific knowledge is made, with important consequences for the authority and authenticity of research findings. Through a collection of case studies, this volume encourages methodological reflection on whether and how historians of science and STS scholars might recover contributions to the human sciences. Ultimately the volume asks how our professional, institutional, geographical and political circumstances condition whom we claim to speak of and for.