The girl that lives in France is middle class and and stress free and still wants more stuff wants to live a rich live
They get a letter form his boss saying he is invite to a rich party with his wife she asks him for money and he gives her 400 franks to buy a new dress then she goes to her friend and asks for a pixie of jewelry she get a big diamond necklace.
She goes to the party and talk to many rich people they don't even mention the necklace but the other people just want to talk and have a good time the leave and she loses the necklace
They are trying to find the necklace and they cant so they freak out about it
They buy the necklace for 46 thousand franks he spent his live saving and they are now poor she runs in to the friend