The challenge of preparing novice primary teachers for teaching in an educational environment, where science education has low status and many teachers have limited science content knowledge and lack the confidence to teach science, is great. This paper reports on an innovation involving a sustained simulation in an undergraduate science education course as a mediational tool to connect two communities of practice--initial teacher education and expert primary science teaching. The course lecturer and student teachers role-played the expert classroom teacher and primary students (Years 7/8) respectively in an attempt to gain insights into teaching and learning through authentic activity that models good practice in primary science teaching and learning. Activity theory was used to help frame and analyse the data. Findings from the first trial indicate that the simulation was very effective in initiating science pedagogical content knowledge (PCK) development of primary student teachers.