This paper studies intersectional multiplicity by encompassing the ways individuals shape relationships between social structures and their science identity. We discuss the science lives of two sixteen-year-old British South-Asian Muslim women studying in a single-sex independent school in London, both of whom aspire to science careers. Adapting McCall's 'intracategorical complexity' in favouring a case study approach, we present the multiplicity of our participants' relationships with exclusion and inequality, discrimination and privilege within their lived social settings, and how these relationships shape their identities and ambitions to become scientists. Our findings reveal that despite their similarities in their societally ascribed intersectional makeup, Ayesha and Hanya differ in viewing their intersections as challenges and/or opportunities. They both portray agentic control towards 'going against the grain' as future women scientists by negotiating their intersections as they develop their science identity.