Mark Of An Angel

Meet Elsa. She's under a lot of stress. Her husband has left her and they're arguing over custody of their son, Thomas (Arthur Vaughan-Whitehead) - he threatens to bring up her 'history'. Despite everything, she's doing her best to be a good mother. But when she takes Thomas to a fancy dress party, she sees a little girl there, and a strange obsession unfolds.

It starts with questions to Thomas, carefully put - who is this girl? What can he find out about her? Wouldn't he like to go and play with her older brother? Soon she's inviting herself into the girl's home, or creeping around it outside at night, watching. Alarm bells begin to ring for the girl's mother. What is going on?

Mark Of An Angel is a powerful, character-based thriller in the manner of Hitchcock classics like Marnie and Vertigo. Parts of it are hard to believe, but we're told it's based on a true story, and the performances are convincing throughout.

Catherine Frot is compelling as the obsessed woman, at once loving and threatening - even when we are afraid of what she might do, we feel for her and don't want her to get caught. Sandrine Bonnaire, as the girl's mother, turns in an equally powerful performance, more understated at first but just as complex. The masterful script will keep you guessing throughout, wondering who to trust, as the fragile girl hovers around them.

Where a lesser film-maker would have been tempted to use simple physical violence and introduce crude motives like profit or revenge, Mark Of An Angel's Safy Nebbou keeps his head and maintains a tight focus, which ultimately packs far more emotional punch.

The film he has created in unusually unnerving without needing to resort to any of the usual tricks. Bright daylight sequences will make your skin crawl. And through it all, for all that he's sidelined, there's the humanising presence of Thomas, asking by his very existence where Elsa's attention ought to be.

This is a fine example of two great actresses getting to show what they're made of, and it's an intriguing, haunting film.