'The Necklace of Pearls,' in Silent Nights: Christmas Mysteries

"This is a classic ‘country house at Christmas’ short story, first published in 1931. Sayers’s regular sleuth Lord Peter Wimsey is spending the festive period at a house party hosted by a rich and genial old man who loves to have his guests play classic parlour games like Hunt the Slipper and Sardines. During a game of Animal, Vegetable or Mineral? he notices that his daughter’s priceless pearl necklace has disappeared from the side table where she had put it for safety. A search quickly reveals that none of the guests have pocketed it and it’s not anywhere in the house, yet nobody has left the property nor been alone for more than a few seconds. It’s up to Wimsey to track it down, and while I don’t want to spoil what is really a very clever ending, suffice to say that it’s a very appropriately seasonal solution."