Everything that happens is set in Paris in the 1800s, Madame Loisel wants to look better for people and what she has now isn't good enough for her, she always wants more, she seems very greedy.
Monsieur Loisel gets him and his wife to a fancy party, but her problem is that she does not have anything fancy enough to wear to the party, and her husband sacrificed some money for her to get a new dress.
Madame Loisel decides to borrow a diamond necklace from her rich friend, Madame Forestier, and then went to the party having the time of her life while her husband slept in another room.
After the party Madame Loisel went home in a rush not to be seen with "rags" as she says, after the couple got home she had realized the necklace was gone.
They both had to lie to her friend and had to buy one that was 38,000 francs and so they grabbed it promising to pay it back and they replace it and give it back to her friend.
Over the next ten years the couple had been doing work paying off the loans they used for buying the necklace and Madame Loisel had encountered miss Forestier and Loisel tells her friend that she replaced it after losing it, and after that she find out it was worth 500 francs.