Kirsten Blohm was born in an American prison in Germany 1946. Searching for her roots, she uncovers the truth about her mother Signe Gondrup and her affair with a German officer - whom Kirsten believed to be her own father. The German Secret is a story set in war-torn Europe about captivity and flight, secrecy and lies. The film follows Kirsten Blohm's journey in her mother's footsteps as she unravels the mystery of her origin. A journey that unveils a series of dramatic events and has far wider repercussions than she could ever have imagined.