Video is used widely to support teachers' learning and enactment of responsive instruction. Informed by principles of video club design, we designed a video club to support secondary science teachers developing a vision of responsive teaching, attention to student thinking, and a critical discourse to analyze their own and others' efforts to enact responsive practices. In this study, we investigate if and how teachers developed a critical discourse in this context. Analysis reveals that the group developed a more collaborative, interpretive, and evidence-based discourse about teaching and learning. These findings contribute to research on video clubs as a professional development model to support teacher learning, as well as make visible how teachers shifted to develop a more critical lens for discussing teaching and learning. This study has implications for designing professional learning that will result in sustained, generative development in the context of instructional reform.