This book examines the lives and accomplishments of two Irish sisters, Edith and Florence Stoney, who were pioneers in the use of new electromedical technologies, particularly X-rays but also ultraviolet radiation and diathermy. The Stoney sisters were instrumental in the development of these technologies. In addition, the story is structured around a number of intertwined themes that are based on the experiences that the sisters had throughout their lives. Their upbringing, shaped by their father’s progressive worldview as a scientist, served as a foundation for their subsequent lives. Their Irish heritage was shattered when Ireland gained its independence. Their professional experiences, which were satisfying for Florence because she was a qualified doctor but frequently frustrating for Edith because she was a Cambridge-educated scientist, mirrored those of other aspiring women during this time period, which was characterized by the expansion of the suffragist movement and the formation of women’s lobby groups. The conditions brought on by World War I created an environment in which their unusual specialist knowledge was in widespread demand, and the book devotes considerable attention to analyzing the sisters’ experiences during the war. But ultimately, this is the extraordinary story of two sisters who are close but independent, and the love and support they have for one another that has endured throughout the years.