This thesis documents my exploration of professional development of four experienced English language teachers of diverse background taking the MA TESOL programme at the University of Manchester. Having considered professional development to be about change construed broadly to professional identity and teacher beliefs, I explored it through a series of individual in-depth interviews held throughout the programme. The majority of the interviews focused on the teachers' ongoing life and development and allowed the teachers space to make meaning of what they were going through and how they were developing as they engaged in the programme. On the basis of the interviews, stories about the teachers and their year were constructed. Within the stories, I synthesized what I had learned about the teachers' experience and highlighted the changes that I could see had happened to their professional identity and teacher beliefs. The stories provide a vivid example of professional development of experienced English language teachers through a master's degree. They also bring to the fore the significance of future-directed thoughts for how teachers develop professionally, which is rarely acknowledged in the existing literature. I further use the stories as a ground to conceptualize professional development of the four teachers to account for the important role their thoughts about the future played in it. Using the concepts of imagined identity and antenarrative, which I borrow from the literature, I describe it as an iterative pursuit of an ever-evolving imagined identity, or identities, and antenarrative, or antenarratives. Finally, I examine the cases using the conceptualization as a lens and offer some further insights about professional development in TESOL.