Becoming a social justice teacher, for high-poverty urban settings, is fraught with emotional ambivalence related to personal, professional, relational, political, and cultural social justice issues. Prospective teachers must navigate their sense of justice, grapple with issues of educational disparity, engage with theories of critical, multicultural, and constructivist approaches to teaching science, and articulate their vision and philosophy of teaching. Furthermore, their emotional navigation occurs at nested micro, meso, and macro levels. In this article, I present a case study of the historical development of an African-American, Caribbean preservice teacher's social justice stance. Drawing on the concepts of emotional genealogy, critical emotional praxis, and positional identity, I explore why she majored in Chemistry, how she decided to become a Chemistry teacher, and her struggles with notions of oppression and multicultural education. The narratives focus on what emotions Nicole expresses, and how those emotions help Nicole position herself with respect to social justice issues she navigates, from micro to macro levels, in becoming a social justice Chemistry teacher. (Contains 2 tables and 1 figure.)