Cinemas are expecting kids - and adults - to storm screenings across the country on the opening day of Chamber of Secrets.
In a special interview released this week by Warner Bros, JK Rowling said she was thrilled with the special effects.
She also hinted that although the second novel was hard to write, it contained some very important storylines.
"Key things happen in book two and no one knows how important those things are yet," she said.
Loads of screens
The Chamber of Secrets will show on more than 1,000 screens in the UK - that's 40% of all the screens in the country.
And it's already taken £8m in previews in the week before the film's official release on Friday.