It is 1958: Isolde Dahl is a young teacher who goes to work in a British school on the shores of Lake Ploen in north-west Germany. She is returning to a country she fled as a child refugee with her mother, Renate. Her father has disappeared into the chaos of a continent ravaged by war. Isolde has grown up in a Wales both strange and familiar.

1945, Lake Ploen. Michael Quantz is an officer in what is left of a shattered German military command as they stage a last chaotic stand before the Allied armies in the final days of the World War II. Everyone has secrets. Michael wants to survive: his wife and son may still be alive. He will hide, change, become a teacher of music.

As Isolde and Michael meet on the shores of a German lake, the choices they have made and the stories they have told will change their lives again.