[3] Hilary was born in Cheshire,[4] England and later moved to the South East to study for a First Class Honours Degree in History of Ideas.

[7] It won the 2015 Theakston's Old Peculier Crime Novel of the Year Award,[8] and in 2016, it was selected as one of the titles for World Book Night in the UK.

[11] Hilary has written about her family history, most notably in "My Mother was Emperor Hirohito's Poster Child" for The Guardian, March 2014.

[13] She wrote the introduction for Virago's new editions of three books by Patricia Highsmith republished in 2016: The Two Faces of January, This Sweet Sickness, and People Who Knock on the Door.

[citation needed] Her seventh novel, Fragile, published on 10 June 2021, is partly inspired by the motives of Daphne du Maurier's Rebecca.