In the course of engaging with a Mathematics and Science Partnership (MSP) project, we planned a yearlong Leadership Academy that fit under the "train the trainers" model for professional development. Midway through, teacher leaders rejected a traditional conception of leadership based on expertise, individualism, and the transmission of knowledge. This proved to be a moment of critical mass wherein the project was democratically reinvented around a model of shared leadership where teacher leaders were positioned as ambassadors of a culture of inquiry. We were able to document three catalysts for this shift as well as the conditions that existed such that these catalysts could prove effective at producing change. We present here our findings on what happens when we allow teachers to take power and experience agency in a teacher leadership development program. [For the complete proceedings, see ED583989.]