Until the 1960s "blue babies" were a striking sight in our streets. Suffering from congenital heart disease offered a bleak outlook to young patients and a heartbreaking experience for parents. Very few would make it to adulthood; now, in the West at least, most have a much higher chance of survival. In Kate Bull tells not just of the development of heart surgery in children, but of the patients, past and present, whose lives have been transformed. Besides the technology, the sociology of medicine has changed substantially since the 1950s – think of the atmosphere of children’s wards. Other things have barely changed – consider the dread of kissing your child goodbye at the door of an operating theatre in any era. Children’s heart surgery is often seen as a medical triumph; but, for all the successful operations completed, thousands of pioneering patients have gone before, perhaps facing their own uncertain futures. Today, we place great hope in the power of science. Many lives have been saved; but, sometimes, we ask medicine to do more than it can. By turns frightening, heart-wrenching and inspiring, is a powerful story of medical progress, hope and survival.