What is the falling action of 'The Necklace' by Guy de Maupassant?

'The Necklace' is mostly about a woman and her husband who are poor. There is a ball coming up and the woman borrows a necklace from her friend. It is a diamond necklace, then the woman borrowing it loses it and she and her husband spend 10 years paying back depts after they bought their friend a 5,000 frank necklace. At the end, it turns out the diamond necklace that was borrowed were fake diamonds.