J.K. Rowling reveals she's written a fairy tale that's hidden in an unlikely place

J.K. Rowling doesn't do many interviews -- but when she does, she's not afraid to drop a bombshell or two.

In a nutshell, she's written a fairy tale. A political one. It's unpublished, and -- according to Rowling -- is likely to stay that way.

Oh, and it's written on a dress that's currently hanging in one of her wardrobes.

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"The theme of my 50th birthday, which I held at Halloween even though that's not really my birthday, was come as your own private nightmare," Rowling explains in the clip above.

"And I went as a lost manuscript."

Her costume consisted of a fairy tale -- the one mentioned above -- written over a dress. Isn't that the coolest costume you've ever heard of?

"So that book, I don't know if it'll ever be published, but it's actually hanging in a wardrobe currently," Rowling finished.

Just imagine how much that dress would fetch on eBay.