The factors preventing registered nurses from failing students in practice are multifaceted and have attracted much debate over recent years. However, writers rarely focus on what is needed to fail an incompetent pre-registration nursing student in their final placement. This hermeneutic study explored the mentor experience of failing a pre-registration nursing student in their final placement. A total of 19 mentors were recruited from 7 different healthcare organisations in both inner city and rural locations in the southeast of England. Participants (...) took part in individual reflective interviews about their experience of failing a pre-registration nursing student in their final placement. These experiences were interpreted through a hermeneutic discovery of meaning. The new horizon of understanding which developed as a result of this research is framed within the context of moral stress, moral integrity and moral residue with the overall synthesis being that these mentors’ stories presented a new horizon of moral courage. (shrink)