Catherine Carreg has grown up a tomboy, spending her days racing her ponies with Deio, the drover's son, in a small Welsh village. But Catherine is consumed by a longing to escape the monotony of village life and, with Deio's help, runs away to London. Alone in the unfamiliar bustle of the city, Catherine finds a position in a rest home for sick governesses in Harley Street, run by Miss Florence Nightingale. Then, as the nation is gripped by reports of the war in the Crimea, Catherine volunteers as a nurse - and her life changes beyond all recognition. Arriving in Scutari, she is pitched into a living nightmare and, against the passion and heroism of one of the most traumatic wars in history, she is forced to grow up quickly and painfully, and learn the hardest lessons of love and war.