Critics have been dazzled by the magic of West End play Harry Potter and the Cursed Child. The play, written by Jack Thorne and based on a story by Thorne, director John Tiffany, and author Jk Rowling officially opens at the Palace Theatre on Saturday, after beginning its previews back in June.

JK RowlingHarry Potter and the Cursed Child is based on a story by JK Rowling.

The play is presented in two parts and runs at over five hours in total. It follows Potter, now in his mid-30s, and his son Albus, who is just beginning at wizarding school Hogwarts. The play is set 19 years after the seventh and final book in Rowling’s best-selling series.

In the Daily Telegraph critic Dominic Cavendish gave the play five stars and wrote: "British theatre hasn't known anything like it for decades and I haven't seen anything directly comparable in all my reviewing days.”

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The Independent’s Jack Shepherd added: "It's quite apparent this isn't written to be either a book or a tie-in film; it's a spectacle for the theatre, one that is filled to the brim with fan service and magical imagery that will amaze.”

Writing in The Guardian, critic Michael Billington confessed he wasn't very knowledgeable about the wizarding world, but assured theatre goers that this would not hamper their enjoyment. “While it helps to be a paid-up Potterhead,” he wrote. “Tiffany and his team stage the piece with such dazzling assurance that I finally began to see the point of being wild about Harry.”

Variety’s Matt Trueman found the play “spellbinding” and predicted it could do as much for the theatre as the books did for reading over a decade ago. “It is, quite simply, spellbinding: The Show That Lived Up to Expectations – and Then Some,” he wrote.

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“A captivating story given a spectacular staging and – Rowling’s specialty – a big, big heart. Twenty years ago, Harry Potter turned a generation on to reading,” he added. “The Cursed Child could do the same for theatre.”

Most critics also seem to be happily abiding by Rowling’s plea that theatre-goers “keep the secrets” after watching the play, so as not to spoil the plot for fans. However, wether you’ve managed to score a ticket to a performance or not, come Sunday all will be revealed when the paperback version of the script hits shelves.