Director Claude Chabrol offers a bonbon of a thriller with Huppert as the Swiss chocolate-magnate wife of a famous pianist (Dutronc) with a penchant for serving drug-laced hot cocoa to her guests -- including an unexpected visitor who may or may not be her husband's daughter. A stylishly arch dark comedy with shades of Rebecca, Merci stays on the right side of camp with an ambiguous ending that belies Huppert's perfect-wife/nutso grin.

