This paper reports on young women students participation in their undergraduate mathematics degree programme: their gendered trajectory is characterized in terms of their being both "invisible" in the dominant university mathematics community and yet "special" in their self -conception. It draws on data collected from a three-year longitudinal project investigating students experiences of undergraduate mathematics at two comparable traditional universities in England. Specifically, students' narratives are interpreted as providing insights into their defensive investments in their particular ways of participating. An interpretive feminist perspective is used to claim that these young women are involved in the ongoing redefining of the gendering of participation in mathematics, and conveys how they manage to choose mathematics, and achieve in university mathematics, whilst in many respects adhering to everyday views of femininity.