As this book by Jo Osler and Jill Flack makes clear, professional learning has a critical edge in terms of what it means not only for teachers' practice but also for students' learning. These two highly skilled teacher researchers illustrate what is possible when professionals choose to develop and extend their own knowledge in ways that are driven by their concern for the development of their own professional practice in innovative and creative ways. As one reads through the chapters that comprise the remarkable journey that Jo and Jill have had together and have consolidated through writing this book, it becomes immediately obvious that their knowledge, skills and ability combine in ways that lead to meaningful new insights into teaching and learning. Their work is challenging, thought provoking and ground breaking in the way that it both speaks to the world of teaching and learning and creates a vision for the development of teachers and teaching more generally.