JK Rowling on Harry Potter and the Cursed Child
10 June 2016 Last updated at 20:02 BST
JK Rowling's Harry Potter books have sold hundreds of millions of copies and spawned a series of blockbuster movies.
The latest Potter instalment comes in the form of a two-part play.
It's called Harry Potter and the Cursed Child and had its first preview this week.
The BBC's Will Gompertz spoke to the author and the team involved in creating the play.