Inexplicably, Fitzpatrick turned down an offer from the London School of Economics, where the famous Sovietologist Leonard Schapiro held sway, and hadn’t even thought of applying to Cambridge, where the even more famous E.H Carr taught. Instead, she accepted a place at St Anthony’s College, Oxford, known as a hotbed of spies on both sides of the Iron Curtain, where her doctoral supervisor was Max Hayward, a lugubrious anti-communist, who had been sent by British intelligence to help debrief the Petrovs years before.

Fitzpatrick was a shy young woman, but everything to do with her studies brought out her determination. She soon landed a ten-month British Council fellowship to study in Moscow, where she doggedly unravelled looping red tape to reach the government archives. There, she pursued her interest in Anatoly Lunacharsky, a journalist and critic and the USSR’s first People’s Commissar for Enlightenment – minister, in our more prosaic terms, for education and the arts – who eventually fell out of favour with Stalin.

England then was still drab with postwar austerity. Perhaps it prepared Fitzpatrick for Moscow, which was even drabber, almost impossible to negotiate, and bone-chillingly cold. After orienting herself, she did what she had to do to gain access to the grail: permission to work in the Soviet archives. The most helpful thing her Russian supervisor did was introduce her to Lunacharsky’s daughter and, through her, to her uncle, Lunacharsky’s brother-in-law, Igor Sats.

As soon as she met the mercurial Irina Lunacharskaia, Fitzpatrick’s life changed. Despite an age gap, the two women immediately became friends. Lunacharskaia was technically a science journalist, but really she was a force of nature. Flamboyant, talkative, she dressed fashionably, had a huge and expensively decorated apartment, and was impeccably ancien régime in her tastes and manners: everything, in fact, that marked her as a bourgeoise. Nonetheless, she prospered in the Soviet Union, expertly working a vast array of contacts and pulling strings. When she took Fitzpatrick under her wing, all that was at the naïve young Australian’s disposal.

Sheila Fitzpatrick in Moscow, 1968

Igor Sats was something else. A liberal in Western eyes, he was an ‘old Bolshevik’, as Fitzpatrick repeatedly calls him. He remained true to Marxism-Leninism right through its murderous perversion by Stalin and the milder but no less perverse politics that followed. A member of the editorial board of Novy Mir, a magazine of literary criticism, he loathed the political élite. Loyally, he turned a blind eye to his niece’s excesses, but he scorned prestige and took in an endless stream of waifs: poor people, homeless people, people in political and economic trouble. He ran up enormous debts buying medicine on the black market for his ailing wife, but his pockets were always open to others. Nonetheless, he made his accommodations with the state. Almost to the end, he continued to believe that the ideals of communism would one day be realised, and he was intolerant of dissidents who aired the country’s dirty linen in the West.

Sats was also intellectually rigorous and became Fitzpatrick’s chief mentor, opening up a view of the Soviet Union which neither her British nor Australian contacts, or her position in Moscow as a foreigner, could have shown her. She came to understand that Soviet totalitarianism was not monolithic, but a dense interplay of pragmatism and idealism, of intolerance and black humour. People joined the party to advance their careers, and lost their careers for opposing the party on matters of principle. And there was room for people like Sats, never a dissident but an ongoing nuisance for authorities and an existential reproach to the morally corrupt.

Sats’s optimism waned after the Soviet tanks rolled into Czechoslovakia in 1968. The political situation in Moscow tightened, and he was sacked from Novy Mir, along with the editor and most of the board. He didn’t live to see the fall of the Berlin Wall, and would surely have considered the new Russia, with its crony capitalism, its widespread poverty and its jettisoning of high culture, as a turn for the worse.

‘The pages are discreetly studded with fascinating names: Fitzpatrick neither name-drops nor wavers from her narrative line.’

The period between her arrival in Moscow and the shift in mood after Prague makes up the bulk of Fitzpatrick’s memoir. The pages are discreetly studded with fascinating names: Fitzpatrick neither name-drops nor wavers from her narrative line. She comes across the brilliant young art historian Camilla Gray, acknowledging the importance of her enduringly influential book, The Russian Experiment in Art (1962), while damning the woman with faint praise. The dissident writer Aleksandr Solzhenitsyn, who would demonstrate the ambivalence of Soviet intellectuals when he defected to the West to his immediate disillusionment, was part of Sats’s world at Novy Mir. One Day in the Life of Ivan Denisovich was first published there in 1962.

Fitzpatrick is adept at describing atmospherics. In her first memoir, My Father’s Daughter: Memories of an Australian Childhood (2010),postwar Melbourne came alive in small details. In the new book, it is Moscow, in the ritualistic gesture of stripping off coat, hat, scarf, gloves, and boots when arriving at someone’s home, the sourness of public officials (with their belligerent refrain of ‘I am human too, you know’ when required to fulfil the smallest part of their job description), the stink of inefficient sewerage systems. On a trip through the Caucasus, Fitzpatrick marvels at the bright colours the women wear, the extroversion of people’s public behaviour, the wealth of fresh fruit and vegetables in the markets, the cafés selling edible food and wine, evoking a Mediterranean contrast to the grim North. She notes the shrines to Stalin, still Georgia’s favourite son. She doesn’t need to point out the contrast between those bright glimpses, the sense of looseness after the grim grey of Moscow, and the later incarnation of totalitarianism in the newly independent states of the region.

Nostalgia permeates A Spy in the Archives. Fitzpatrick is in constant dialogue with her younger self. Many of the letters she wrote at the time were preserved, and her quotes from them form a musical counterpoint to the memories she retains in her seventies. Her writing is light and wry, a model of style and clarity. She handles the history, the politics, and the dramatis personae expertly, neither patronising the knowledgeable nor mystifying the newcomer. And her cliff-hanger chapter endings, the device comically evident, work: I was unable to resist them, turning just one more page until the early hours.

The tone was spikier in her first memoir; the result, perhaps, of a bracingly unhappy early life. That she adored her father is evident, that she loathed him too is equally evident, and she was alienated from him in the end: a sad predicament for daughters who idealise imperfect fathers. He died while she was in London; she didn’t attend the funeral and afterward felt no need to return to Australia.

In A Spy in the Archives, she finds an emotional mooring in Moscow. Her Russian friends’ interest in ideas, in history, philosophy, and music, were more attractive to her than practical preoccupations of the Anglo-Saxon world. ‘In the 1950s, the Australian professional music world was not an intellectual milieu,’ she wrote in My Father’s Daughter of her time in the Australian Youth Orchestra as a teenager. ‘Sometimes I used to think it was not even a musical one.’ The Russians’ emotional expansiveness, instinctive hospitality, and assumptions about the reciprocities of friendship were more enduringly attractive. Sats’s view of her was certainly erotic, but the relationship remained chaste, and he and his niece filled the emotional void left by Fitzpatrick’s troubled relationship with her parents. To find a mother figure who, while often flamboyantly demanding and constructively critical, was ‘always on her side’ (a locution Fitzpatrick repeats when describing the feeling of being loved), and a father figure who was as obsessive about Liszt and Beethoven as he was about the purity of his old Bolshevik ideals, as well as being warm and protective, seems to have answered multi-layered needs.

Fitzpatrick’s style may be temperamental as much as a matter of skill. She went on to specialise in the social history of the Soviet era, becoming Professor of Russian History at the University of Chicago. Critics of one of her most representative books, Everyday Stalinism (1999), accused her of not fully acknowledging the horrors of the Soviet Union during the Stalin years. If they are right, it may be that matter of temperament. Despite the trail of broken romantic relationships, her loss of family and of country, A Spy in the Archives is narrated in a chipper tone, shifting to wry humour to describe the exigencies of living as a foreigner in Moscow. Only once does she refer to the ‘loneliness and misery’ of her life in London, and then only to provide a foil to her sense of homecoming on return to Moscow.