(FROM AP) ? A card-sized, hand-written 800-word prequel to J.K. Rowling‘s seven-book Harry Potter series is going up for sale at a charity auction in London on June 10. Waterstone’s Booksellers Ltd. distributed a cream-colored A5 paper — each slightly bigger than a postcard — to 13 authors and illustrators, including Rowling, Nobel Prize winner Doris Lessing, novelist Margaret Atwood, and playwright Tom Stoppard. Rowling chose to use her card — writing on both sides — to pen a prequel to the Potter series. Stoppard wrote a short mystery and Atwood was going to fill out her card remotely using a robotic arm controlled by computer linkup. Proceeds from the auction will go to the writers’ association English PEN and the British charity Dyslexia Action. Copies of the cards will also be collated into a book for sale in bookstores and online in August. In December, a handwritten, leather-bound book of fairy tales written by Rowling sold for nearly $4 million at auction. The money went to The Children’s Voice, a charity Rowling co-founded in 2005. (AP via Yahoo!)