The next Harry Potter book is expected to shatter sales records in the United States when it is released next month, its US publisher has told a newspaper.
About 200 million Harry Potter books have been sold worldwide
Anticipation is already building for Harry Potter and the Order of the Phoenix, the fifth in the series, which is released around the world on 21 June.
Publisher Scholastic told the Wall Street Journal it was planning its most extensive ever marketing campaign for the book.
The biggest US bookseller, Barnes and Noble, said the book would be "our largest single seller in the history of the entire company, most definitely".
Scholastic will ship 8.5 million copies of the book to shops in time for its release.
Many stores are organising midnight parties for readers who want to get their hands on a copy as soon as they can.
The marketing campaign will cost between $3-4m (£1.8-2.5m), according to the Wall Street Journal.
The book is already number one in the charts of online retailers Amazon, MSN, AOL and others, one month before its release.
It will be available for $29.99 (£18) in shops but has been available to order for $18 (£11) on the internet.
Special events to mark the release, including costume parties and library events, have been arranged across the world.
The four previous Harry Potter books have sold 200 million copies in 55 languages, author JK Rowling's agent told the Wall Street Journal.