Paris (AFP)

In "Chanson douce", theatrically released on Wednesday, Karin Viard is disturbingly disturbing in the role of the killer nanny whose chilling story earned the French-Moroccan novelist Leïla Slimani the Goncourt prize in 2016.

It is Lucie Borleteau, director of the noticed "Fidelio, the odyssey of Alice" in 2014, who tackles the difficult task of adapting the novel of Leïla Slimani, bestseller who sold about 900,000 copies in France, has been widely translated all over the world and has already been the subject of a theatrical adaptation.

Inspired by a real news event in New York in October 2012, "Sweet Song", co-written by Lucie Borleteau, Jérémie Elkaïm and Maïwenn, tells the story of Paul (Antoine Reinartz) and Myriam (Leïla Bekhti), a couple of Parisian wives, who decide to use a nanny to look after their two children when Myriam wants to resume her work as a lawyer.

They find the rare pearl, Louise (Karin Viard), an experienced and devoted woman, always available. Often absent, returning home late, they can count on Louise. Ready to work the day and night to keep Mila, 5, and her little brother Adam, still a baby, she occupies a bigger and bigger place in their family.

But as she enters their intimacy, this rigid woman will be more and more strange and unpredictable, gradually sliding towards the irreparable.

Terrifying account of a double infanticide - never directly shown - and a critique of our society and the violence of its class relations, evoking both Chabrol's "The Ceremony" and Polanski's "The Tenant", "Sweet Song" mix the genres.

Between a realistic chronicle and a psychological thriller with sometimes fantastic accents, the film slowly slides towards discomfort, while tension is also maintained by the music.

"I like the idea of ​​a permanent ambivalence that hovers over the narrative, between naturalism and fantasy, and which refers to this + disturbing strangeness + of which Freud speaks," says Lucie Borleteau in the press kit of the film.

Popular actress with a likeable image, Karin Viard manages to fit perfectly into the skin of this distorted and disturbing woman, who will be monstrous behind her perfect looks, "figure of absolute nightmare" who "embodies our ancestral fears" , according to the director.

"Louise is a character very different from what I have been able to play before," said Karin Viard, whose nuanced game avoids caricature, without creating empathy. "I have been considered a lot in jovial and truculent women roles and here I embody a more complex character, bitter, black, crazy and violent".

© 2019 AFP