John le Carré, 1963. Alec Leamas's last mission. Cold-War espionage stripped of romance.
From Wikipedia
The Spy Who Came in from the Cold is a 1963 Cold War spy novel by the British author John le Carré. It depicts Alec Leamas, a British intelligence officer, being sent to East Germany as a faux defector to sow disinformation about a powerful East German intelligence officer. As with le Carré's previous novels Call for the Dead and A Murder of Quality, the novel features the fictitious British intelligence organisation, "The Circus", and its agents George Smiley and Peter Guillam.