This book describes design research related to improving public health in a vulnerable community in Rio de Janeiro, Brazil. The research has been done with Intituto Vila Rosário (IVR) that does long-term health work in the community of Vila Rosário. Specifically, it aims at empowering the Community Health Agents working for IVR. The author studied Vila Rosário in depth to elarn how people in the community understand diseases like tuberculosis and their causes. The study developed design products to improve Health Agents' work. Throughout, the study built on participatory and empathic design, but went to their roots in Paulo Freire's pedagogy and Brazilian social design. Fundamental to the research process were the commitment to the context and to its key persons. This book describes many of the lessons on how to build trust in this lovely, complex yet instigative community.