As Soviet tanks rolled into Budapest in 1956, a wave of refugees spread across the continent seeking safety. One of those was Suzanna, who arrived in Britain in 1956 “after she had lied to the Austrian police about her age and name.” She later becomes Susanna — dropping the “z” that marked her Hungarian origins — a small but telling reinvention that foreshadows the life of concealment and adaptation she will lead.

Susanna is a central figure in Karla’s Choice, a new George Smiley novel written not by John le Carré, but by his son Nick Harkaway. The novel is set in the period after the death of Alec Leamas in The Spy Who Came in from the Cold but before the events of Tinker Tailor Soldier Spy. During this uneasy lull in the Cold War, Susanna has built a secluded, but comfortable, life in London where she works in a modest publishing firm run by a Mr Banatai. When a killer arrives from Moscow Central, Susanna begins to understand that life hitherto was layered with deceit.

To help unravel these layers, George Smiley himself comes in from the cold. Smiley, who has been living his own comfortable life in the loving arms of his perpetually unfaithful wife, Ann, is persuaded to come back to the Service. He does so out of a misplaced sense of duty and a misplaced hope that he can reconcile with the ghosts of his past.