When John le Carre’s novel Tinker Tailor Soldier Spy was broadcast as a seven-part BBC television adaptation in 1979, it was a sensation. The British public avidly followed George Smiley, le Carre’s aging, cuckolded, not-very-James-Bond-ish spymaster, as he hunted a Soviet mole in the highest level of the British secret service. The series is justifiably iconic, but to watch it today is to be slightly puzzled at its runaway success. The pacing is slow; the plot, conveyed often in flashbacks and expository dialogue that goes on for minutes at a time, is famously confusing; and the speech of upper-class English spies appears, to modern ears, bizarrely arch, almost fey.

But that’s the whole point. Viewers didn’t love the show despite these things: They loved it for them. The show’s esoteric vocabulary (“the Circus,” “lamplighters,” “scalphunters”) and its mastery of tone felt authentic and even seductive. Viewers, like the readers of le Carre’s novel, felt like members of the world’s most secret and high-stakes club.