As wedding bells peal across the English countryside, Christabel makes a commitment to married life in a country soon to be at war with her own.

Trapped in Germany by the outbreak of war, Christabel finds herself at the mercy of Allied air raids and Peter's secret work is put at risk when she takes in two house guests.

As Peter's secret work becomes increasingly dangerous, Christabel takes the boys to the safety of the Black Forest but is forced to return to Berlin by some terrifying news.