I like French cinema and Sophie Marceau in particular, so i was expecting great things of this film, but i have to say i was disappointed. It's not awful, but it's not great either - the first half of the film is pretty poor, but it redeems itself to some degree in the latter stages.
After the first half hour i thought i had paid to see a soft-porn flick, such was the lack of plot, direction and character. Not a lot happens to begin with except Marceau s****ing every bloke who glances her way, plus the occasional scene with her infirm mother - a broken woman who chose duty over love in her choice of husband. The film then progresses to chart Marceau's path along the duty vs. love road, although it does so in a very contrived way.
The characters are fairly one-dimensional, and it's not until the last hour or so that there is any real emotion to the film. By this time the director seems to have lost the plot, and the film changes tone very noticeably (think: From Dusk 'til Dawn - ok maybe not that bad, but bad enough). One minute it's a drama, then it's an action flick. Then back to drama again, and very disjointed it is too. It finally ends back in the drama fold, and does at least ask a few questions about the theme of the film, Fidelity, but for a film that's 3 hours long they're not very deep and not very well portrayed, and i left the cinema thinking: "what a missed opportunity!". Disappointing.