Juliette Binoche is both a serious actress and a luminous movie star. She has always moved back and forth between star vehicles – like the 2007 American film, Dan in Real Life, where she plays widower Steve Carrell’s love interest— and arthouse fare, such as Krzysztof Kieslowski’s Blue, her breakout role. In her latest film, Safy Nebbou’s Who You Think I Am, she combines both of those personas — the glowing beauty and the actress who often brings out something surprising in the text — in a stylish entertainment where she shines at every moment. The movie, which combines comic elements with a psychological thriller, works best when it sticks with social commentary and comedy and is at its weakest when it moves into melodrama and moralizing. It’s as if the director and screenwriters want to punish us for laughing at some of the situations with tragic, upsetting plot turns. Binoche plays Claire, a Parisian literature professor with a great apartment – the movie is terrific real-estate porn – and nearly grown sons who don’t need her much anymore. Much of the story unfolds as she speaks to her therapist (Nicole Garcia) as tries to figure out how to deal with the fact that she is aging and alone. Claire is still recovering from the breakup of her marriage and is upset that her ex-husband (Charles Berling) is now with a woman who could be his daughter. It’s hard to imagine a universe in which Claire would not be receive a great deal of attention from men but, like her ex, Claire is drawn to people who are much younger and she is becoming frustrated with being dumped and ghosted. She tells her therapist that for her, social media is both “a shipwreck and a life raft.” When the latest 30-something man she is seeing disappears on her, she decides to fight back. Although she teaches 18th century literature, such as Pierre Choderlos de Laclos’ Les Liaisons Dangereuses, a chronicle of diabolical manipulations by cynical lovers that has been retold many times, her revenge takes a very 21rst century form: She creates a fake dating profile of Clara, a beautiful woman in her early 20s, and she makes sure her former boyfriend sees it. But is it is his roommate, Alex (François Civil) who is intrigued by the profile and writes to the woman who is pictured. Soon Alex and Claire as Clara are having an intensive relationship by text and by phone, including phone sex. Claire is both delighted and unsettled by the relationship. When Alex presses her to meet in person, she has to decide how far she wants to take it. At this point the movie, which up till now has been fun, a kind of giddy journey through the fulfillment of a fantasy that is easy to imagine, turns dark and a bit sour. I won’t reveal any spoilers, but it becomes clear that Claire is not the most reliable narrator and that not everything she tells her therapist is true. I felt that her impulse to play this game was human and understandable – she wanted to live the fantasy of being a young object of desire again – but somehow the movie seems to want to scold her for her desire. The final third of the movie is far less enjoyable than the earlier part, and the turn towards tragedy (or melodrama, depending on how it strikes you) seems to come without any payoff in terms of insight or depth. The message seems to be that it’s bad to lie, but we already knew that.Binoche is graceful and compelling, even when she is at her most unhinged. Civil, who plays Hippolyte on the very funny Netflix series, Call My Agent!, is so likable and decent that you do feel for his character, who could have been shallow and dull. Garcia, a veteran actress/director, conveys quietly that it is possible to grow older with style and dignity. While the movie doesn’t work all the way through, most of it is a treat and it showcases some very real problems – as well as solutions that are to be avoided at all costs.