A beautiful girl as innocent and pure as the blue sea almost becomes a dissolute and promiscuous female spy overnight. Which intelligence agency has such an unparalleled trick that could expedite the transformation of this young girl? What are the little-known stories behind this? In fact, the answer is already well known to many - it's the world-renowned Soviet Union's intelligence agency, the "KGB". The story of the girl transforming into a female spy was revealed unintentionally by a Soviet female spy who defected to the West. She disclosed the inside story of the KGB's sexual training courses.