Patriarchy is a threshold concept in women's studies--a significant, defining concept that transforms students' understanding of the discipline. This article reviews our design, implementation, and findings of a lesson study crafted to teach women's studies students the complex idea of patriarchy as a social system. We analyze the lesson using both quantitative and qualitative analysis, in keeping with the ideals of feminist pedagogy, suggesting a new model of SoTL research for the women's studies field.