In the brief golden years before the outbreak of World War I, Rosie McCosh and her three very different sisters are growing up in an eccentric household in Kent, with their neighbours the Pitt boys on one side and the Pendennis boys on the other. But their days of childhood adventure are shadowed by the approach of the conflict that will engulf them on the cusp of adulthood.

When the boys end up scattered along the Western Front, Rosie is left confused by her love for two young men – one an infantry soldier and one a flying ace. Can she, and her sisters, build new lives out of the opportunities and devastations that follow the Great War?