Elsa Valentin (Catherine Frot) is driving home one day when a fire engine races past her car, sirens blaring, and once further up the road she discovers why: a large blaze in one of the buildings, which brings back uncomfortable memories for her. She is currently in the middle of a divorce, and her husband Alain (Michel Aumont) is looking to get custody of their young son, reminding her that he does not want to bring up her history of mental instability but will if it's necessary. She insists she is sane, but the next day when picking up the boy from a birthday party she catches sight of a little girl - and is immediately obsessed.
The last thing we see in this film before the end credits start to roll is a caption saying that this film was based on a true story, and if it had stopped fifteen minutes before we could well have believed it. Alas, there's that problematic ending to contend with, something which tips over what has been a delicate balancing act into outright preposterousness and all the sterling work of the two lead actresses, Catherine Frot and Sandrine Bonnaire, is sadly undone. Before that occurs, it is possible to enjoy a tense psychological drama which keeps threatening to transform into an all out thriller, but never quite does, and the release that might have offered would have been much more to the film's beneifit.
But then, it was based on that true story, so perhaps director and co-writer Safy Nebbou was sticking to the facts, however hard to swallow they turn out to be in a fictionalised setting. It's odd how we as an audience can accept such plot twists and coincidences when they are treated to a different build up, but here under Nebbou's classy, restrained guidance little about the conclusion rings true. Still, there are the actresses to enjoy, and Frot offers a reading that suggests beneath her calm - too calm - exterior there is a lot of pain and anguish going on, while Bonnaire, as Claire, the little girl's mother, is convincing as the suburban mum who finds life taking a sinister turn when Elsa introduces herself.
And it is Elsa making inroads into this family's life, which she manages to do through her son's friendship with Claire's son, giving Elsa the excuse to do more than simply hang about outside the house staring through the windows hoping for a glimpse of the girl. Claire and her husband are selling their home as they plan to emigrate to Montreal, and Elsa bluffs her way in by telling them she's interested in buying, even though she has nowhere near the required funds to pay for it. But she does not let on to Claire about that, and soon her fixation on the girl has her turning up at an ice rink to join in with her skating, resulting in the girl taking a tumble when Elsa gets carried away at her delight of being so close to her.
It gets worse, as the woman also shows up at a ballet performance the girl is appearing in, and in a weirdly comical scene Claire is in the audience watching the stage when she notices Elsa standing in the wings. This has all the signs of exploding into a Fatal Attraction type suspenser with mums, but it does not turn out that way and begins to fizzle once we are privy to the real reason Elsa is so preoccupied with the child. We were right in thinking that she has been through a terrible trauma that has affected her perspective, and you can probably guess much of what that is from about the first ten minutes, but when Nebbou goes on to confirm her suspicions it's a step too far. Maybe if he had ditched the whole true story tag and come up with a better way to bring all the threads of the story together then complaints about what does actually happen would not be valid, but this is too much of a damp squib. Music by Hugues Tabar-Noval.