The Scottish writer Naomi Mitchison worked as a Voluntary Aid Detachment nurse during the First World War, serving on wards for several months before she left to nurse her wounded husband. Using previously unpublished archival material, this article argues that Mitchison's experience as a nurse contributed to her career in crucial ways, by encouraging her to develop empathy towards others across barriers of class and nationality, and by drawing her towards fictions of estrangement (from historical novels to fantasy and science fiction). The paper argues that the trauma of the war encouraged the estrangement of Mitchison's debut novel The Conquered, a historical novel, and that this trend in her writing continued as she turned to science fiction later in her career, questioning the extent to which social pressures such as inequality and the class system shape bodies, their health care, and their horizons of thought.