This is the incredible story of Elzbieta Zawacka, the WW2 female resistance fighter known as Agent Zo. Agent Zo was the only woman to reach London from Warsaw during the Second World War as an emissary of the Polish Home Army command, and then in Britain she became the only woman to join the Polish elite Special Forces, known as the 'Silent Unseen'. She was secretly trained in the British countryside, and then the only female member of these SOE affiliated forces to be parachuted back behind enemy lines to Nazi-occupied Poland. There, whilst being hunted by the Gestapo who arrested her entire family, she took a leading role in the Warsaw Uprising and the liberation of Poland.

After the war she was demobbed as one of the most highly decorated women in Polish history. Yet the Soviet-backed post-war Communist regime not only imprisoned her, but also ensured that her remarkable story remained hidden for over forty years. Now, through new archival research and exclusive interviews with people who knew and fought alongside Zo, Clare Mulley brings this forgotten heroine back to life, and also transforms how we see the history of women's agency in the Second World War.