Smiley next reappears as a minor but pivotal character in "The Spy Who Came In from the Cold", his third novel. Smiley is revealed to have come back into the service of the Circus as the top aide to Control, Maston's mysterious successor as the Circus' chief. It's revealed that, following the events of "Call for the Dead," Smiley and Guillam succeeded in turning Mundt, the sole survivor of the spy ring, into a British double agent, and sent him back to East Germany. Fearing that Mundt's cover is about to be blown, Smiley and Control manipulate agent Alec Leamas into posing as a defector and sending him to Germany under the assumption that he is going to orchestrate Mundt's death. Along the way, Smiley learns that Leamas blew his own cover to his girlfriend, a nineteen-year-old communist sympathiser named Liz Gold, and arranges to incorporate her into the plot. Although Liz's unwitting role ultimately ensures the mission's success, it also results in her death, prompting a grief-stricken Leamas to give up and let himself be shot dead at the Berlin Wall as Smiley attempts to extricate him.