She’s got the look that penetrates

One silent look from the French actress Ludivine Sagnier can tilt a cinematic world on its axis.

In Claude Chabrol’s “A Girl Cut in Two,” in theaters today, Sagnier plays Gabrielle, a TV weather girl in love with a married novelist (Francois Berleand). As a birthday treat, this jaded Lothario, twice her age, ushers her upstairs at his gentleman’s club, where she’s to pleasure his friends. Vaguely aware of his plan, and self-destructively complicit, Gabrielle downs her drink as realization dawns on her face. Chabrol makes the point that she’s an angel in a cave of devils.

That look is the queasy center of a film that uses the manipulation of a young woman to launch a sardonic attack on the decadence of the literary intelligentsia, the superficiality of the television world and the self-entitlement of the bourgeoisie. The latter is represented by an unstable scion (Benoit Magimel) of New Money. His relentless pursuit of Gabrielle ends in a tragedy inspired by the 1906 Stanford White murder case.

Sagnier, 29, has a 3-year-old daughter with actor-model Nicolas Duvauchelle, and they’re expecting another child in December. She says motherhood won’t interrupt her work, which has embraced diverse roles in such films as “8 Women,” “La Petite Lili” and “Peter Pan.” American moviegoers probably know her best from 2003’s mystery thriller “Swimming Pool,” which also starred Charlotte Rampling. Sagnier’s image -- bronzed, bikini-clad, promiscuous -- earned her a reputation as a screen temptress, despite the fact that her reckless character crumbles in the wake of a killing.

Asked if that film changed her life, Sagnier laughs. “First, I lost weight for it . . . no, I’m kidding,” she says. “It had an impact on my career more than my life. It got recognition internationally, so it allowed me to reach a lot of people, which was positive. But it was a test for me to play this sexy, confident girl, because it’s not who I usually am. I don’t have a sex symbol image in France, because people there don’t dwell on nudity -- they just like or dislike the character.”

Sagnier is fully clothed in the club scene for “Girl Cut in Two,” but naked emotionally -- another test, “because I’m full of imagination,” she says. “I guessed that the most horrible thing was going to happen. It was as difficult as being naked on screen. You don’t see what happens, but you feel the perverse atmosphere.

“This is a trick of Chabrol’s. He wants the audience to project whatever it wants on the scene, because he says that nothing is dirtier than the eye of the observer. He pushes this naive and ambitious girl to cross boundaries that aren’t easy to cross. That’s where we see how innocent and devoted she is -- I think that’s moving.”

Sagnier gives another unforgettable “look” in Claude Miller’s “A Secret,” a true-life drama set in Nazi-occupied France, that opens Sept. 12. She plays Hannah, a young Jewish mother, whose husband lusts after her sister-in-law. Hannah is sitting poolside when she sees him gazing at the woman, a beautiful swimming champion. She immediately comprehends the situation, but Sagnier’s expression only faintly registers shock. She saves her revenge for later.

“My concern was not feeling empathy for Hannah,” Sagnier says. “Because if I couldn’t, it wouldn’t have been realistic. I had to keep my heart tough. But one thing I like about the movie is that it’s too complex to say who is guilty and who’s a victim.”