In the brief golden years of the Edwardian era the McCosh sisters--Christabel, Ottilie, Rosie and Sophie--grow up in an idyllic household in the countryside south of London. On one side, their neighbors are the proper Pendennis family, recently arrived from Baltimore, whose close-in-age boys--Sidney, Albert and Ashbridge--shake their father's hand at breakfast and address him as "sir." On the other side is the Pitt family: a "resolutely French" mother, a former navy captain father, and two brothers, Archie and Daniel, who are clearly "going to grow up into a pair of daredevils and adventurers." In childhood this band is inseparable, but the days of careless camaraderie are brought to an abrupt halt by the outbreak of The Great War, in which everyone will play a part.