Merci pour le chocolat (2000) - Chabrol

When the young Jeanne finds out that she could have mistakenly been exchanged, from her cradle, with another newborn (the son of a famous piano player), she decides to contact this family, not really thinking that this could be the truth. After she tells this to the presumed father and the rest of the family, even the son of the piano player starts having more than one doubt about his origins, and all this will lead to the discovery of a murder committed many years before by the second wife of the musician. The story is a pretext to dramatize the misdeeds and the hypocrisy of the French upper class members, shown without pity: the coldness between the family members, hidden by a false happiness; the lack of real feelings; the unbearable 'bon ton' of the mother, and so on.