We meet Mathilde, and learn about her dream of being wealthy and glamorous. M. Loisel delivers the invitation to the ball to Mathilde, who throws a minor fit and gets him to buy her a dress. She borrows the diamond necklace from Mme. Forestier.
Mathilde goes to the fabulous ball. She and her husband return home at 4am, and discover the necklace is missing. M. Loisel and Mathilde spend the day searching, and find nothing.
After a week of searching, M. Loisel and Mathilde decide they have to buy a new necklace. They do, and get buried up to their eyes in debt. The Loisels fall into poverty and spend ten years paying off their debts. One day Mathilde meets Mme. Forestier on the Champs Elysées and learns the necklace she lost was a fake.