JK Rowling has written a prequel to Harry Potter, but you won't be seeing it in bookstores any time soon.

The 800-word prequel will instead be one of the items in the What's Your Story? charity auction to be held on June 10 at Waterstone's Piccadilly in London. The event is run by Sotheby's.

The end of the tale ends with Rowling writing, "From the prequel I am not working on - but that was fun!"

Update 6/12/2008:
The auction is over and the prequel sold for $48,858.