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As Harry Potter and the Cursed Child starts its previews, JK Rowling has urged fans to #KeepTheSecrets.
The author appears in a new video pleading with early audiences not to spoil any of the play's "surprises that [have been] built into the story".
She also wrote on Twitter: "Potter fans have always had each other's backs. Today I'm asking you to #KeepTheSecrets of #CursedChild."
Based on an original story by Rowling, the play comes from Jack Thorne and is directed by John Tiffany.
The new production at the Palace Theatre in London will focus on the boy wizard's youngest son, Albus Severus, as he struggles to deal with his dad's legacy while living in his shadow.
Taking up the title of The Son of The Boy Who Lived is Sam Clemmett, who has previously starred in The Musketeers, Doctors and Holby City.
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Jamie Parker, Paul Thornley and Noma Dumezweni will portray the grown-up Harry Potter, Ron Weasley and Hermione Granger in the new play.
Harry Potter and the Cursed Child will officially open on Saturday, July 30 at the Palace Theatre in London.
