Ans: When Mme Loisel and the others realized the necklace was gone, they sought to figure out where she might have dropped it. They concluded that it could have been left in the cab. They had no idea what number it was. As a result, Loisel walked back over the path they had taken. When he couldn't find anything, he went to the cops and cab companies. He even placed an ad in the newspapers promising a prize. He then ordered Matilda to write Mme Forestier, a letter stating that she had damaged the necklace's clasp and that she would have it fixed. This allowed them to search for the necklace. They did, however, decide to replace the necklace with a new one in the end.