They say that falling in love is a kind of madness. Certainly the victim becomes blind to glaring defects in the one and only.

Senta (Laura Smet) tells Philip (Benoit Magimel) that proof of true love has four conditions: plant a tree, write a poem, sleep with a member of the same sex and kill someone. Philip tries to laugh it off. Tree, poem? No problem. Bed with a bloke? Well, let's talk about that. As for killing... who? Anyone, Senta says, a stranger; it doesn't matter. "It's a gesture that places us above ordinary people."

Philip realise that she is serious and so admits to a murder he did not commit. She, on the other hand...

Shades of Strangers On A Train linger in the dusty crevices of this absorbing thriller, based on a Ruth Rendell novel. Director Claude Chabrol is a past master of creating the setting for criminal activity, building tension from a base of relative normality. First: introduce the cast. Second: watch the characters enact their everyday lives. Third: find a spanner and drop it into the works.

Philip lives with his glamorous mother and two sisters, one of whom is about to marry a civil servant. He is good at his job, good with people and yet not entirely happy at being the responsible male in a household of high-spirited women.

It is at the wedding that he meets Senta, a first cousin of the groom, and one of the bridesmaids. She tells him that she took one look and there was never any doubt. "I have waited all my life for you," she says. He is too overwhelmed by the seductive power of her commitment, after no more than a glance across a crowded room, to sit down and question the sense of it.

She lives in the basement of a vast, deserted house that she says she owns, where a woman who calls herself her mother, but isn't, practices ballroom dancing in a bare room on the first floor with a younger man who resembles a South American bandit. Already too besotted by Senta's sexual intensity, Philip finds himself ensnared.

The film stalks the audience, who may feel restless at the start, waiting for something to happen. Chabrol lays down clues that will be claimed later and it is only at the end that the subtlety of the plotting can be fully realised.

Sensible people will ask, "What on earth was he doing with such a nutcase?" Have sensible people never felt the insatiable hunger of infatuation?