The action takes place in an old castle where four people live : an old gaga lady who became crazy after her husband's death and who thinks she is Mrs Lafarge ,a notorious poisoner;her daughter ,Alix,married to an alcoholic ;and a servant. Enter Agnes who married Alix's brother ,who left the castle a long time ago to lead a bohemian life (we're told he is a painter).Agnes came to see her mother-in-law -that's what she says- to get some money to help the artist who ,like so many others,seems to be broke .