I'm very interested (slowly building up a library) in cold war espionage - no one does it better than the Russians. The present tense is not an oversight, the Lubyanka is still the tallest building in Moscow as the saying goes.

To me the Soviet Union represents this kind of philistinic failed experiment (Lenin was literate which therefore elevates him above Hitler?) come horror movie that is simultaneously terrifying and yet very fascinating.

One of the strangest things one finds in books about Soviet spies (double agents or not etc.) is that often the only photos of them in public taken with state blessing and thus surviving are those taken by the Soviet internal security services.

I find Soviet aircraft design quite interesting too, in the sense that even just in the cockpit designs you can see the work of designers making do with relatively limited budgets. In a flight simulator it becomes obvious that US planes are almost easy to use whereas Russian cockpits are one size fits all (i.e. training vs design costs)