In your story, consider how you might challenge, expand on, or reimagine the themes of The Wizard of Oz. Writing about a well known story can be difficult, because you want to bring a fresh perspective that the reader hasn’t heard before. On the other hand, it can make writing the story easier because you may not have to include much exposition.
Your story can take place in our world, such as the real example of the slippers located by the FBI. Or, your story can take place in the world of The Wizard of Oz, or another world of your invention. You simply have to include an object from the original story–the rest is up to you!