The title of John Lanchester’s new book makes a welcome change in the recent rush of family memoirs and all the assorted thuggery and buggery inflicted on their poor authors by alcoholic or insane mothers, fathers, siblings, aunts and uncles. Lanchester even admits, ‘I had a happy childhood.’

He was born in 1962 and ‘by the time I was three years old, I’d lived at ten different addresses in six different countries’. Novelists, and Lanchester is a very good one, often have a dislocated start in life. Indeed, his whole life has a rather older, anachronistic feel to it than you would expect from someone only in his mid-forties. His parents came from two worlds which seem immeasurably far away now: his mother was from the priest-ridden Ireland of the Twenties, and his father, born in Cape Town, spent most of his life in Far Eastern outposts of the British Empire. Lanchester’s book is a recreation of his parents’ lives and an expression of love. But it is also an investigation of family secrets and lies – not many sons discover that their mother had been a nun, not once, but twice, and that she was, quite literally, not who she said she was.

The book falls into three parts, and of these the most fascinating is the first: the extraordinary story of Lanchester’s mother. Born Julia Gunnigan in 1920 (the date takes on a crucial and mysterious resonance in her story), she came from a family