Not a spy thriller by any means but a look at the entire system of espionage: Your Face Tomorrow

Javier Marias's three-volume novel, Your Face Tomorrow, really picks up in the 2nd half of vol 1, Fever and Spear, as we see that the narrator, Deza, has been subtly brought into the world of espionage. After the long first section, in which a mentor asked Deza to observe a guest at a dinner party and then engages him in a long discussion about the guest and his date, we understand that this whole observation request was a test, which Deza passed: He's subtle and observant and gives an excellent, detailed report on his observations. In the second half of the volume, the man he observed - Tupra - suggests that maybe he can provide some work for Deza that will pay more than his current shaky job at the BBC. He's invited into an interrogation as a translator - Turpa and another man are interviewing a man who is or seems to be a Venezuelan general, and he's talking to them about getting support and backing for a planned coup. After the interview, Turpa does a lengthy post mortem w/ Deza, though officially Deza's only role is that of translator. But it's another test, which D passes, and we see that he's now part of the world of espionage and international politics. As we've always known about this world, nobody is fully trusted nor fully entrusted with all the information at hand; also, we have known - and we see in action - that everyone is closely observed by someone else, not necessarily someone of superior rank. There are multiple layers of truth (and trust), in a system in which the capture or turning of any one agent couldn't do too much damage, as nobody has complete knowledge. The writing and observations feel authentic and credible; this is not a spy thriller by any means - largely devoid, so far, of action and risk - but it's an insight into a way of life, seen through the eyes or an intelligent man at a point of crisis in his life: marriage breaking up, living in a foreign land, suddenly brought into situations or potentially great risk and peril.