A standout for me was the story of Peggy Lambert, about which there is virtually no information online.

A SIS spy and a wife of a fellow intel officer[1], before they had to evacuate during the soviet occupation, she became the person who has smuggled the first ever minox Riga cameras[2] to the West from Riga, Latvia.

Afterwards, these cameras became a staple amongst the espionage gadgets.

The other thing (which has deeply disturbing) was the stories of torture of captured agents, which is another reminder that there is more to intel gathering than just boredom and risk. When it goes wrong, it goes really wrong.

[1]: en.m.wikipedia.org/wiki/Kenneth_Benton [2]: www.spymuseum.org/exhibition-experiences/about-the-collection/collection-highlights/minox-riga-camera/