This two-year study examines an emergent model for promoting classroom change amidst systemic professional development efforts--the hybrid teacher leader (HTL). Utilizing ecological and teacher social network frameworks, the relative strengths and weaknesses of educators who both teach and lead teachers are explored. In-depth qualitative data from six HTLs across four Washington state school districts are examined to look at the ways that HTLs navigate and shape the change-oriented professional development environment, as well as the conditions under which the "teacher" and the "leader" are synergetic. Findings include that HTLs have a significant capacity to serve as a bridge between multiple subgroups within the larger educational system, making them an essential human resource within their environments. At the same time, role confusion, mismanagement of time and tenuous relationships across the sites reduced the impact of HTLs on colleagues' professional learning--necessitating sharp intentions and boundaries to maximize efficiency. (Contains 4 tables and 1 figure.)