Celia Walden

“As a mother you’re only allowed to talk about the ‘good’ moments – not the ones when you’ve had enough and want to be on your own,” she explains.

“Or just want to be a woman, not a mother. So I think more provocative than writing about this brutal murder is writing about the place of the mother in today’s society.” She pauses.

“You see, I don’t believe in maternal instinct” – a provocative statement from a woman in the early stages of pregnancy.

“I just don’t believe that a woman is naturally closer to her child than a man. Not at all. I think maternal instinct is a male construct that has been used for centuries to keep women in their place, at home.

“Even in art, that relationship has been magnified. So women are either sensual or maternal, gazing lovingly at their children. The woman who rejects both of those roles and is neither a mother nor a whore doesn’t exist. So we need to invent [her].”

The daughter of a teacher and a banker who moved to France when she was 17, before working as journalist, Slimani has always found inspiration in real events.

Although her son’s nanny “is the most sweet-natured woman – and I’m a little worried about her reading the book”, the writer remembers overhearing her parents talk about the nanny she had in Morocco until 13, “and them saying that it had become ‘almost dangerous’ and ‘suffocating’ the way she had insinuated herself into our family’.”

So was that the real seed for the book? “Absolutely. Because this woman never got married or had children. She had sacrificed her life for us – and for what? Nothing. Cruel to say, but true. And I think the sadness I witnessed then was a big part in the creation of my character, Louise.”

Slimani’s fictional nanny clearly has a psychotic breakdown after years of mistreatment at the hands of her late husband and former employers. The parents of the two children she murders, however, are kind, if occasionally unthinking and condescending in a way that will make anyone who has ever paid for child-care cringe with recognition.

Did Slimani mean the book to be a class commentary? “Certainly on how, in our bourgeois society, we pretend that class doesn’t exist.