The Mitrokhin Archive is an interesting book giving insights into KGBfs activities abroad.
The most interesting part is how KGB the interfered in the world champions in chess with hypnosis involved to beat the opponent. (Korpov vs. Korchnoi)
Furthermore, in another story, an English "granny" (Melita Noorwood) was a spy for the KGB for over 40 years. The English government decided not to take her to court because of her old age.