English teachers and teacher educators worldwide have engaged in various continuous professional development (PD) activities to catch up with the development and challenges of their profession. In Indonesia, for example, English teacher educators who are also faculty members are pressured to publish in internationally-indexed journals. Fortunately, nontraditional PD models that are more personalized and timelier for educator's needs are available. One such model is interactive online PD formats, particularly online PD communities, where knowledge is not merely received but also constructed and shared among participants. However, it is still unclear why members remain in such communities and how they sustain their engagement. Situated in the Third Space framework, this case study focused on an online PD community of 33 Indonesian English teacher educators. The study attempted to determine why these teacher educators participated in the community and remained involved over an extended period. The findings revealed two main reasons why they joined and stayed in the community. Also, the community served as a Third Space where members felt empowered to present contradictory voices against government-sanctioned PD discourses. Some critical implications of the findings are addressed.