Anne-Marie Duff reads the thrilling true story of Ursula Kuczynski, one of the Soviet Union's most significant spies. From acclaimed historian, Ben Macintyre.

Abridged by Richard Hamilton
Produced by Emma Harding

Episode 3: In 1938, 'Agent Sonya' is posted to Switzerland, from where she plots an assassination attempt on Adolf Hitler.

Opening music: Kühle Wampe oder Wem gehört die Welt? Solidaritätslied by Hanns Eisler from album Bye-Bye Berlin, performed by Quatuor Manfred, Harmonia Mundi
Closing music: Suite No 2 Op 2 Niemandsland i by Hanns Eisler from album Roaring Eisler, performed by H K Gruber and Modern Ensemble, RCA Red Seal Show less