La Cérémonie(1996)

The Lelievres are well-heeled, fashionable, and cultured -- a typical bourgeois family, steeped in the usual problems of upper-middle class life. After many failed attempts to find a suitable housekeeper for their country chateau, Catherine Lelievre retains Sophie, a prim young woman who cares for the family with a quiet, if unsettling, efficiency. Against her employers' wishes, Sophie strikes up a friendship with the local postmistress, Jeanne, a sly, loose cannon seething with hatred for the upper class in general, and for Catherine's husband Georges, in particular. The friends quickly form an intimate and insidious bond, buoyed by dark secrets. Jeanne uses Sophie to provoke the Lelievres, and Sophie -- emboldened by Jeanne's destructive impulses, unleashes a sinister and rebellious underside.