The Harry Potter and the Cursed Child script is flying off UK bookshelves - and not because of any witchcraft or wizardry.
The playscript has sold 680,000 print copies in the UK in its first three days of sale, making it the fastest-selling book in a decade, according to The Bookseller.
It's beaten Fifty Shades of Grey, which sold 664,478 print copies in the same period back in 2012. In fact, the last time a book sold quite this quickly was - you guessed it - Harry Potter and the Deadly Hallows back in 2007.
If the Cursed Child continues to sell at this rate, it will become the second biggest-selling single week for one title since records began. Harry Potter and the Deathly Hallows, which sold 1.8m copies plus 780,000 of the adult edition in its launch week in July 2007, currently holds the record.
The play, written by Jack Thorne and based on an original story by JK Rowling, Jack Thorne and John Tiffany, is also selling well overseas. In the US, publisher Scholastic said the title had sold 2m copies in the first 48 hours, sales the company have called "unprecedented" for a playscript.