The part of Moscow Centre most often referred to in le Carré's novels is the fictional Thirteenth Directorate headed by Karla, the code name for a case officer who has risen and fallen from political favour several times and was at one point "blown" by the British in the 1950s. Karla and George Smiley meet while Karla is in prison in Delhi, with Smiley trying to persuade Karla to defect during an interrogation in which Karla gives nothing away. Karla refuses these advances and eventually returns to favour in the USSR, masterminding the Witchcraft/Source Merlin operations supporting the mole Gerald in the Circus. Karla possesses a cigarette lighter given to Smiley by his wife, which he took during Smiley's interrogation of him.