An employee holds a Finnish edition, part of an auction lot containing 550 international copies of works in the Harry Potter series, at Bloomsbury Auctions in London Feb. 26, 2008. (Xinhua/Reuters, File Photo)

JK Rowling's 800-word handwritten prequel to the Harry Potter series will be auctioned on June 10, alongside other storycards written by 12 other A-list authors.

Waterstone's Booksellers Ltd. says the cream-colored A5 papers — each slightly bigger than a postcard — were distributed to 13 authors, including the boy wizard's creator J.K. Rowling, Nobel Prize winner Doris Lessing, novelist Margaret Atwood and playwright Tom Stoppard.

Rowling used both sides of her card to write a prequel to her seven-book Harry Potter saga, while Lessing penned a story about the power of reading. Stoppard wrote a short mystery and Atwood was due to fill out her card remotely using a robotic arm controlled by computer linkup.

The storycard finishes with the words "From the prequel I am not working on – but that was fun!" and is signed J. K. Rowling, 2008.

Gerry Johnson, managing director of Waterstone's, said: "We never dreamed that JK Rowling would donate something so precious. I can't begin to guess how much it will raise at auction." The plot is a closely guarded secret.

The prequal is likely to raise hundreds of thousands of pounds for charity at auction at Waterstone's flagship store in central London. "There is just no telling how high the bidding will go," said Philip Errington children's books specialist at Sotheby's.

One of seven handwritten copies of Rowling's book of stories "The Tales of Beedle the Bard" netted 1.95 million U.S. dollars for charity in 2007, the highest ever price achieved at auction for a modern literary manuscript.

(Xinhua/Agencies May 29, 2008)