In partnership with the Center for Urban Epidemiologic Studies, andin collaboration with diverse institutions and individuals, the Centerfor Community Problem Solving completed a study of the health of 431 undocumented Mexicans in New York City. Informed by a robustly democratic rebellious vision of problem solving and by adecidedly unorthodox rival theory of undocumented Mexican migra- tion, the study reveals patterns that, if fortified by further investigation, might well change how we think about the health of undocumented Mexicans, how we allocate resources, and how we target interventions. In this Article, Professor Gerald P. López analyzes how this study – more accurately, the effort of which the study is a part – aims at once to close two gaps: the gap between what we now know and what we might learn about the health of undocumented Mexicans in New York City, and the gap between what we typically do now through our practices and what we might do through a rebellious vision of problem solving.