The Necklace

"The Necklace" is an 1884 short story by Guy De Maupassant.

A young, lower middle class couple borrows some nice clothes and jewelry from an upper class friend to wear to a party. During the course of the party, the lady loses a diamond necklace. Hiding the truth, the two sell their house and all their possessions and work for the next twenty years to pay the friend back, only to be told at the end it was costume jewelry, and worth only a couple of dollars at the most.

Tropes used by the story:

 * An Aesop: Basically, know your place. Or honesty is the best policy.
 * Broken Treasure: Deconstructed.
 * Karmic Twist Ending
 * Mock Millionaire
 * Never Lend to A Friend
 * No Doubt the Years Have Changed Me: When the lady meets her friend again at the end of the story, the friend doesn't recognise her at first because of all she's gone through to pay off the necklace.
 * Shaggy Dog Story: This story's version of the trope is so strong, it nearly crosses over to Shoot the Shaggy Dog territory (if the reader wasn't laughing from the story's cruel irony). What saves it from that extreme is that the situation could have been very easily avoided, had the couple admitted that they lost the necklace in the first place.
 * Storm in A Teacup: Played for drama.