In this article, we analyse a script of an imagined classroom interaction from the perspectives of politeness and positioning. The script was written by a prospective teacher, Cara, as part of her Lesson Play. The Lesson Play was prompted by her reflection on how the needs of students who are disaffected with mathematics might be met, an issue that arose for her during teaching practicum. She developed a lesson plan to address this issue and scripted an interaction that she envisaged might arise during its course. Our analysis revealed Cara’s sophisticated awareness of the ways disaffected students use language to manage their face needs and also of the multiple positions and storylines that can be at play even in a short interaction. It also revealed her own storyline as a beginning teacher of mathematics. The analysis prompted us to consider the extent to which we invoke prospective teachers' insights and storylines in our courses, and how we might use these to support deeper examination of practice. We suggest that Lesson Play, particularly when based on teaching practicum, has the potential to reveal understandings and beliefs about mathematics teaching and learning that may not be captured elsewhere.