Embedding setting (subject-based ability-grouping) into the primary school environment creates structural conflict--physically and culturally--fundamentally changing the nature of primary schools through the imposition of secondary practices and cultures and the loss of pastoral care. This article examines the hidden implications for teachers and pupils of taking on secondary school roles within the primary school context. It highlights the wide-ranging, yet nuanced impacts of the use of setting, examining the shift towards subject-based thinking and the erosion of the pastoral-centred holistic ethos of primary education.