Smiley, now fortified with new information, goes to confront Jim Prideaux, an old spy who long since came in from the cold and is now a school teacher. Control, in his last days, seemed to have confided in him and sent him on a mission behind the Iron Curtain to find out who exactly the mole in the Circus was, Tinker, Tailor, Soldier, Rich man, or Poor man.

Smiley now has the information he needs and starts to stir things up with the men of which Control suspected one to be the mole. He is able to eliminate two, himself and one other. The waiting begins, when suddenly the message arrives that Prideaux has disappeared.

The waiting has paid off and the traps closes on Karla's mole. It is agreed to trade him against several English spies who were captured by the KGB, but Prideaux is still not found and he has an open account to settle with the mole. With the command structure of the Circus hollowed out and containment in progress, Smiley cannot come in from the cold but remains to pick up the pieces.