No doubt remains; a mole has infiltrated the highest level of the Circus, code name for British Secret Intelligence Service. Sidelined agent George Smiley is covertly tapped to root out the traitor-a task that requires an intensive dig through the labyrinths of Cold War espionage and his own past. Stellar ensemble casts bring John le Carre's thrilling tales of Cold War-era espionage to vivid life in these television classics.