It was late at the dimly lighted Chacha club. Sitting apart from revellers decked out in various combinations of distressed jeans and sequins was a woman in a sober tweed suit. Im sorry, said the womanCatherine Deneuvebut this is our only chance to meet. She had just returned from a shoot in Belgium and was preparing for another one elsewhere in France. Deneuve,the legendary and perhaps most ethereal beauty of France,has come down to earth in her latest film,The Girl on the Train; she plays a sad widow,one of the least seductive roles in her long career. It was directed by André Téchiné,a significant lure for Deneuve. The filmmaker and the actress have been allies since she starred in his Hôtel des Amériques (1981) as a moody woman mourning a dead lover. Since then the two have made six movies together in which she has played various members of mysteriously unhappy families. Téchiné describes her as his cinema sister. The Girl on the Train is based on a true story and adapted from the play La Fille du R.E.R. by Jean-Marie Besset. The Belgian actress Émilie Dequenne plays Jeanne,the daughter,and Deneuve plays Louise,a plain housewife worrying about her daughter,who provokes a scandal. The story is based on true events from 2004,when a girl,who was not Jewish but claimed to be the victim of an anti-Semitic attack on a Paris commuter train,went to the police with cuts on her face and a swastika drawn on her stomach. She had invented the story,and her pose brought out a fear of anti-Semitism in French society. This is not a thriller, Deneuve,66,said. You know from the start that the girl lies. Its hard to picture Deneuve,the blond goddess,as a baby sitter,fettered to her daughter,bogged down by her past. But the mother-daughter relationship is at the heart of the film, she said. Its not a very alluring or sunny part,but shooting with Téchiné is always enriching. Deneuve has had privileged relationships with many of her directors since she played Geneviève,the provincial shop girl whose lover goes off to the Algerian war in The Umbrellas of Cherbourg (1964). She and her sister,Françoise Dorléac,were the darlings of their epoch. They did a bewitching sister act in Demoiselles de Rochefort and each starred in films by François Truffaut and Roman Polanski. But at 25,Dorléac was killed in a car accident. Deneuve became the seductress of her generation,working with a host of filmmakers,making some great films and some less wonderful ones. Ive been lucky to work with filmmakers at the high point in their careers,when their desire matched my appetite, she said. Over the years she has followed her heart more than once: she married the English photographer David Bailey and had a son,Christian Vadim,with the filmmaker Roger Vadim and a delicious daughter, Chiara Mastroianni,with Marcello Mastroianni. I have no regrets, she said,then hesitated. Or not that many. I did miss out on working with Hitchcock. He died before we could make a movie together,and I regret it,but Im philosophical. Catherine has a hidden side,like a Hitchcock actor,like Cary Grant, Téchiné said. We never know what shes thinking. Thats the mystery of her greatness,and her eroticism. Catherine stands on the edge,is tempted by the void,looks down,but holds herself back from falling in the black pit. Ever since they first met,they have worked intuitively. If she had inhibitions,she lost them with me, he said. I used to direct actors as if they were marionettes. I couldnt direct her like that. She changed my way of directing,and Id like to work with her for the span of a lifetime. Thats my secret fantasy,a filmmakers fantasy.