Loosely inspired by the case of Melita Norwood, the KGB’s longest-serving British spy, who was outed aged 87 in 1999, Jennie Rooney’s third novel is a meditation on the secrets we keep for – and from – the people we love. Joan’s mother, a nurse in the First World War, is fond of describing her youth as an ‘unprecedented time’, and it is this phrase that resonates with Joan as she escapes a life of suburban domesticity for Cambridge and a scientific career. A combination of youthful idealism and an encounter with the bohemian Sonya pulls her into the circle of a group of student communists, and it is there that she encounters Sonya’s cousin Leo, whose attraction will come to define her adult life. 

Rooney switches between the past and the present, where Joan has succumbed to the quiet existence she fled in her youth. Now a grandmother, there is no indication that she ever led a double life until MI5 show up one morning with questions about old friends and the work she