In the gripping chamber thriller Merci Pour Le Chocolat, director Claude Chabrol leaves most of the psychology to the great Isabelle Huppert, an actress who always keeps her cards close to her chest, discreetly bottling her true feelings and motives until the last possible moment. She's not unreadable so much as she invites several different readings at once, which gives her a slippery and uniquely compelling screen presence. As the meddling second wife of a classical musician, Huppert reads at times like a black widow and at others like a figure of fun, an intensely vulnerable and vengeful woman driven by love, jealousy, and a pathological need to maintain her domestic bliss. Wasting no time in his 48th feature, prolific French New Wave stalwart Chabrol opens with Huppert's wedding to the world-renowned pianist Jacques Dutronc, which sends the gossip mill into high gear over the mysterious car accident that killed Dutronc's beloved ex-wife. When the wedding photos appear in the newspaper the next morning, a long-buried family secret comes to light for 18-year-old Anna Mouglalis, who is told about a mix-up at a hospital clinic that briefly led Dutronc to believe that she was his newborn daughter. As a gifted piano prodigy in her own right, Mouglalis finds the prospect tantalizing enough to pay him a visit, upsetting Huppert and his untalented son Rodolphe Pauly, who is understandably resentful that she has more in common with his father than he does. After she catches Huppert, the heiress of a chocolate empire, purposely spilling a canister of hot chocolate, Mouglalis sneaks a sample to her boyfriend at a crime lab, which tells her it's been spiked with Rohypnol. Of the New Wave directors, Chabrol was the one most directly influenced by Hitchcock, and he treats the homemade chocolate like the master's classic bomb-under-the-table scenario, in which the audience sees a danger that the characters do not. Yet in a quietly diabolical twist, Huppert isn't labeled a killer, per se, but a disturbed and insecure woman who goes to great lengths to keep her family and her business in order, especially when she senses them slipping away. Chabrol handles the upended family dynamic beautifully until the final third, when a wildly implausible sequence of events lessens the suspense just as he should be turning the screws. But Merci Pour Le Chocolat ends on a note of disquieting uncertainty, adding a few more pieces to an incomplete puzzle.