Ursula Kuczynski, AKA Agent Sonya, is one history's most effective spies. As an intelligence gatherer for the Soviet military, she helped to usher in the age of Mutually Assured Destruction during the bloody 1940s.
In 2020, a newly declassified document muddied the waters - who was Sonya really working for?
In this two-part True Spies story, a new theory deepens the mystery of her life and work.
In Part 1, Sophia Di Martino joins Professor Anthony Glees to follow Sonya's rise to prominence within the Russian GRU.
From SPYSCAPE, the HQ of secrets. A Cup And Nuzzle production. Series producer: Joe Foley. Produced by Hannah Dean. Music by Nick Ryan.
Learn more about your ad choices. Visit megaphone.fm/adchoices