Recommended by Malcolm Gladwell in Tim Ferriss show: Tinker Tailor Soldier Spy door John le Carre. 

Complex spy story. Only got me hooked halfway through. I was close to giving up.

The English is challenging sometimes. Very dense sentences. Not sure I will read another one soon.

From Poland he applied successfully for a post at the Budapest Academy of Sciences and for the next eight years he lived the nomadic life of a minor left-wing intellectual in search of light, often liked but never trusted. He stayed in Prague, returned to Poland, did a hellish two semesters in Sofia and six in Kiev where he had a nervous breakdown, his second in as many months. Once more the Nursery took charge of him, this time to dry him out. He was passed as clean, his networks were given to other fieldmen and Roy himself was brought into the Circus to manage, mainly from a desk, the networks he had recruited in the field.

…

He gave me a drink and we sat there like a pair of schoolboys making up a code, me and Control. We used Tinker, Tailor.