The film is based on the true story of Special Operations Executive French-born agent Odette Sansom, who was captured by the Germans in 1943, sentenced to death, and sent to Ravensbrück concentration camp to be executed. Despite this, she survived the war and testified against the prison guards at the Hamburg Ravensbrück Trials. She received the George Cross in 1946, becoming the first woman to do so and the only woman to do so while still alive. (From Wikipedia, licensed under CC-BY-SA)