Every time the words Harry and Potter are thrust into the media, there are wild gasps across the world as fans of J.K. Rowling's iconic wizard rush to lap up the next instalment of the multi-million pound franchise.

Following on from the triumphant opening in the West End of the two-part play Harry Potter and the Cursed Child on the 30 July, a book of the playscript from the show became available in bookshops at the strike of midnight the same day. The eighth chapter in the Harry Potter tale, titled Harry Potter and the Cursed Child, is a departure from the classic novel form that enthusiasts have grown used to, rather it is a book of the Special Rehearsal Edition script of the play. It hit the shelves at the weekend in time for a midnight release on Saturday 30 July, which was also Harry Potter's birthday of course.

The play follows the lives of Potter et all 19 years on from where J.K. Rowling left them reeling from the aftermath of the battle at Hogwarts. Harry is now working at the Ministry of Magic, still dealing with the issues of the past, whilst at the same time, his son Albus is trying to overcome the fame brought on by his iconic family name.

Whilst the story may carry all the trademarks of Rowling's imaginative narrative but this script has not been written by her but by the show's scriptwriter Jack Thorne and director John Tiffany after developing the storyline with Rowling. This has not stopped the madness that occurs only when Potter returns, with bookstores putting on elaborate displays, pre-ordering thousands of copies and opening at midnight to accommodate demand.

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Fran Plagge poses after becoming the first person to buy the Harry Potter and the Cursed Child script book in Waterstones bookshop in Piccadilly, central London during the midnight party on 31 July for its publicationDaniel Leal-Olivas/Getty Images

Never before, at least in the last 100 years, has a playscript had this effect across the world, with Barnes and Noble declaring it their biggest preordered book since 2007's Harry Potter and the Deathly Hallows. It has topped the Amazon charts for books and Kindle downloads and is at the top of the book charts in the UK. Over 150 Waterstones opened their doors at midnight, as well as a number of WH Smiths, Daunts and Foyles, who were packed out with eager Potter fans.

Speaking to Market Place, Mary Amicucci, chief merchandising officer at Barnes & Noble Inc said: "From the minute the book was announced, it was Barnes & Noble's belief that everyone was going to want this book, regardless of the format, we never considered the format an obstacle for this book."

For publishing house Little, Brown, who published the script book, it is a momentous occasion as it is the first of the Potters not to be handled by Bloomsbury. On the night of the launch, CEO David Shelley said to The Bookseller: "It's the biggest print-run Little, Brown has ever done – and we hope it will be the biggest-selling play script ever."

Harry Potter and the cursed child
Foyles bookshop stocking up on copies of Harry Potter and the Cursed Child script bookRob Stothard/Getty Images

A big leap for a publishing house to join a franchise that already sold 400 million copies in 68 languages, particularly with a format that is so used to being picked up for academic purposes rather than mass appeal and to succeed in doing so. Little, Brown could not comment specifically on sales figures following the release but from the sights of book shops across the UK and US over the weekend, chances are the sales figures are looking good.

The West End play has been given rave reviews with five stars from the likes of The Telegraph, Guardian and Independent. The sell-out run has now been extended until the end of 2017 so far, and there are plenty of fans queueing up to catch a glimpse of the newly imagined Potter family on stage, but opinions have been mixed by those reading the lines on paper.

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The entrance of the Palace Theatre that is staging Harry Potter and The Cursed ChildJack Taylor/Getty Images

Ten-year-old Toby L'Estrange was first to post his review of the play for Amazon after speed reading it in 59 minutes following the release. "It's a very complicated story," he said. "It happens in different times, so it's really helpful if you know all the other books and characters quite well (I do − and so does any other true Harry Potter fan)."

However, the early reviews that followed were less than complimentary with Amazon users describing it as a "lacklustre finale", as well as being a parody of the original seven titles and questioning how much input J.K. Rowling had in the script. But the review tally as it stands on Amazon is 314 positive reviews to 262 negative, so it is balancing out quite evenly at the moment.

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Piles of script books went on sale during the midnight release of Harry Potter and the Cursed Child in WaterstonesDaniel Leal-Olivas/Getty Images

At this point, it must be noted that the version was launched at midnight on Saturday is the Special Rehearsal Edition that, like the books made into films before it, may slightly differ to the actual lines that theatre goers may experience. It is also not the only version to be published and the a definitive collector's edition will be released as well, although a publication date has yet to be announced.

Whether the frenzy will be as great a second time round is yet to be seen but knowing Potter fans, The Cursed Child will probably still be at the top of the literary charts anyway.