JK Rowling has told fans the last instalment of the Harry Potter books could be out in about two years' time.
The author said she planned to start writing it at the end of the year - no sooner, as her daughter is still young.
But she did say she was doing some work on the seventh book at the moment, and repeated that the final chapter is already finished and locked away!
JK was talking at a press conference in Edinburgh where all the reporters were children aged between eight and 16.
After the press conference, fourteen-year-old competition winner Owen Jones, from Cardiff, then quizzed JK in the only main interview she will give during the Half-Blood Prince's release.
The best-selling author told Owen she was dreading finishing the seven-part series, as writing Harry Potter had been such a big part of her life for so long.
"I am dreading it in some ways," she told him. "I do love writing the books and it is going to be a shock, a profound shock to me.
"Even though I have known it is coming for the past fifteen years, I have known that the series would end, I think it will still be a shock."
But she did have some good news for Potter fans who can't imagine waiting another two years to find out what happens to Harry and his friends. She said that, more than ever before, the end of the sixth book will leave big clues as to what's to come in book seven.
JK arrives at the castle
"I think I give very clear pointers as to what Harry will do next," she said. "There is plenty to guess at... at least one thing I think people will probably deduce, there is a mystery left at the end, but I think they might already know the answer if they think about it."
JK said that the Potter books were incredibly important to her, but she also said she sometimes regretted that her life would never be the same again.
"I cannot complain at all, what a fantastic thing Harry Potter has given me.
"But one of my regrets would be that I will never again have the pleasure of sneaking into a cafe, any cafe I like, sitting down and diving into my world and no one knowing what I am doing and no one bothering about me and being totally anonymous."
Of course, there were questions the author refused to answer because they would give too much of the final plot away. She didn't answer how she thought up the special bond between Harry and Voldemort, or how much of a part Fawkes plays in book seven.
Owen's interview also included some guest questions from celebrities, such as Stephen Fry, who voices the Harry Potter audio tapes in the UK, Ministry of Mayhem's Holly Willoughby, singer Lemar and the government's Chancellor Gordon Brown.