The Necklace of the Executed Queen

More than two hundred years ago, the adventuress Jeanne de La Motte carried out a scam with the famous necklace of the French queen. De La Motte met the end of her life in Russia. So, maybe it was here that she hid Marie Antoinette's necklace?.. Zhanna Okuneva discovered a secret stash in an old stove in a house set for demolition, where there were only a notebook and a postcard.

What if this is the key to finding the treasure?

However, having a key is not enough; it would be nice to know which lock it opens...