Mathilde realizes she lost the necklace after she and her husband return home from the ball. As she prepares to take off her evening wrap, she looks in the mirror and notices that the necklace is no longer around her neck. This moment of realization is filled with panic and dread, as she understands the gravity of losing such an expensive piece of jewelry.
Her husband, Monsieur Loisel, immediately retraces their steps in an attempt to find the necklace. They search the streets, the cab they took, and even the ballroom, but all efforts prove futile. The loss of the necklace marks a turning point in their lives, leading to years of hardship and sacrifice as they work to replace it.