Jessica Fellows is the New York Times bestselling author of the iconic Downton Abbey series and the niece of its creator, Lord Fellows. She also received well-deserved fame as a unique expert on the life of Great Britain in the 20th century.

1920. Louise Cannon desperately seeks to escape the clutches of poverty. Her salvation is to become a nanny in a famous aristocratic family. Here she becomes close to the lord's eldest daughter, Nancy, a girl smart beyond her years. Together, they become embroiled in the investigation of the mysterious murder of a World War I heroine, a sister of mercy, on a train in broad daylight. Thus begins the story of the Mitford sisters, six real-life women, notorious throughout the world...