Here is an utterly bizarre fictionalised biopic of Canadian singing star Céline Dion, whose opening scenes will have audiences screaming and running out of the cinemas the way they were mythically supposed to have done at the Lumière brothers’ first silent movie about the arriving train. Even now, I still can’t believe I have seen it.

Valérie Lemercier (from Claire Denis’s Vendredi Soir) directs and stars, playing Aline Dieu – a made-up version of Dion – the youngest of 14 children in Quebec, all the kids kept in line by their formidable working-class mum Sylvette (Danielle Fichaud). Young Aline shows precocious singing talent and her parents send a demo tape to ageing record producer Guy-Claude Kamar (Sylvain Marcel), a version of the real-life René Angélil, who is to become her manager, husband and soulmate as Aline begins her ascent to mega-selling glory, culminating in the Titanic theme My Heart Will Go On and legendary Vegas residencies.

Now … you may be wondering: which actor plays Aline as a child? The answer, horrifyingly, is Valérie Lemercier herself! Her face is digitally superimposed on to the body of a girl between 10 and 12, a face first glimpsed impishly peering over the edge of a stage. Why? Why in the name of all that is holy do that? For a terrifying instant, this looks like a biopic of Jimmy Krankie, or a horror film. Lemercier’s weirdly grinning, gurning face superimposed on the child’s head creates an unnatural chill that the film fails to shrug off, even after Aline as an adult is supposed to be glammed up with her teeth fixed. It does at least create a point of interest in what is otherwise a desperately bland TV-style film. But that opening section is the scariest thing since The Omen.

• Aline is released on 2 March in cinemas.