The mechanisms by which talking therapies exert their beneficial effects are largely unknown. In exploring the process of a talking therapy, motivational interviewing (MI), when used to treat and prevent low mood in stroke survivors, we developed, what we believe to be, a novel approach to analyzing transcripts. We illustrate the method using qualitative data from MI sessions with 10 stroke survivors. The approach, drawing on grounded theory, incorporated processes of parallel and serial memoing among a team of researchers to allow a process of validation. This enabled us to describe session content and to develop theoretical interpretations of what was occurring in and across MI sessions. We found that this process can be used to integrate different perspectives in theory building, allowing for a richer description and more robust theoretical interpretation. Others can use and adapt this approach to develop insights into their own inquiry.