Awareness of teacher scripts is of crucial importance to reflection on practice, and represents one means of widening the scope of classroom performance. The first part of this work provides a full description of three scripts employed by a novice science teacher within the topic of The "Structure of Flowers", and offers a detailed illustration (including a transcription excerpt, a routine, three scripts and an improvisation) of how these were derived by means of a Modelling Instrument (MI). In the second part, the relationships between beliefs and actions are explored through tree diagrams. Finally, there is a discussion of how entrenched scripts may act as obstacles to professional development. (Contains 11 figures.)