Agatha Christie began her life in Torquay, the kind of prosperous seaside resort that would become quintessential Christie territory. Ashfield, the large villa where she was born in 1890 and spent her childhood, provided the model for many of the houses in which her stories are set – hidden within acres of garden, domestics toiling below stairs, family tensions in the drawing room. In her new biography of Christie, Lucy Worsley rightly makes much of Torquay’s tug on the spirit and affections of Christie. With her vast earnings, she bought a Georgian house, Greenway, just along the coast from Torquay, overlooking the River Dart (it is now owned by the National Trust).

Worsley is interesting on the importance of houses to Christie, who assembled a substantial property portfolio. In the country-house-murder-mystery genre of which she is the reigning queen, Christie makes homes places of both safety and menace. In her first novel, The Mysterious Affair at Styles (1920), the pedantic Belgian Hercule Poirot is summoned to a gloomy half-timbered English manor house thronged with secrets. When Agatha and her husband, Archie Christie, moved to a similarly gloomy house near the golf course in Sunningdale, they called it The Styles, in homage to the setting of her successful first novel.

She had married Archie in 1914 but they didn’t properly live together until after the war. Agatha spent the war years working in a pharmacy and, so the legend goes, developing her knowledge of poisons. Worsley provides an engaging depiction of Archie, who emerged from the war a