In France in the early 1900's her and her husband were mid class they get invited to the ball, but since Mathilde doesn't have jewelry, she asks her friend to borrow her some.
After the ball, Mathilde realizes that that she wasn't wearing the necklace, they go out to find it but unfortunately they can't.
They end up going to a store to buy a similar necklace, they work for ten years to pay the 34k francs in debt.
After Mathilde works for herself to be able to get more money, she looses her beauty.
After years of not talking, they run into each other and talk, Mathilde tells her about the necklace and how she has had to pay 34k francs for it. Her friend tells her how the original was only 500 francs since it was an imitation.