If a young couple hire an apparently perfect nanny to look after their two young children, allowing them to return to the carefree world of socialising and professional fulfilment that they once enjoyed … well, in theory, that nanny could just turn out to be a thoroughly nice person. But in the movies she must gradually reveal herself to be a sinister weirdo. This strained and unsatisfying bad-nanny drama is by the French film-maker Lucie Borleteau, who directed Fidelio: Alice’s Journey, a weird sex-aboard-a-container-ship drama
It is based on the Goncourt-winning bestseller by Leïla Slimani, in turn based on a real-life murder case. Myriam (Leïla Bekhti) and Paul (Antoine Reinartz) are a lawyer and record producer in Paris whose relationship is creaking under the strain of two young kids. So they hire a nanny (after the traditional “audition” montage) and this is the prim, brisk, efficient Louise, played by the estimable French character actor Karin Viard. Inevitably, lonely and envious Louise conceives an unwholesome obsession with her employers’ happy home – and the casual well-being that she has made possible.
Lullaby is a curious film. It doesn’t deliver the ruthlessly crafted genre thrills of Curtis Hanson’s 90s Hollywood gripper The Hand That Rocks the Cradle, because it isn’t sure how satirically detached or unsympathetic it wishes to be towards Louise; neither does it deliver the icy and sustained Haneke-esque horror that it appears to promise in its first shot of a sleeping baby. And the satirical issue of a working mother’s supposed guilt is also a bit of a dead letter. In the real case, the nanny was an immigrant – not here, so that satirical avenue would appear to be closed off.
There are some startling and shocking scenes, especially one involving octopuses, and Viard’s performance is good. But there is something disconcertingly redundant about this movie, which pulls its punches with the final grisly scene.
• Lullaby is released in the UK on 10 January.
