The Moscow Rules
en.wikipedia.org
en.wikipedia.org
The implicit artifice of Le Carrés yellow chalk and thumbtacks and poplars and meeting at 7 or 17 past tge hour.. they're not that different to "son of the charm" and magic tricks with coins and rhythmic paused speech in Kipling's "Kim"
They can't be very important or Le Carré would have been warned off.