This case study documented ways that participants in an urban high school collaborated to develop a Connected Coaching approach to literacy learning in the content areas. Analysis of interviews, observations, and archival documents provided detailed descriptions of ways the literacy coach and teachers worked together to integrate content concepts and literacy strategies. At the high school, the literacy coach served as a catalyst for professional growth. This study examined the progression of collaboration toward instructional improvement across a two-year period. Collaboration with individuals grew to include clusters of colleagues teaching the same subjects, and then to involve grade-level teams. Within these limitations, this study suggests a practical approach for other coaches in similar settings and helps illuminate the dynamics of professional development at the secondary level. (Contains 1 note.)