If you're in London and a huge fan of Harry Potter, tonight is the night you've been waiting for. The very first preview performance of the highly-anticipated stage play Harry Potter and the Cursed Child debuted. The play won't officially open until July 30, but fans have been eagerly awaiting the eighth official story in the Harry Potter canon. Tonight we have the first early reactions, and, thankfully, they heeded J.K. Rowling's spoiler warning.

Earlier today, J.K. Rowling posted a YouTube video where she plead with fans to keep the secrets that will be unveiled in this story. Of course, we likely won't know for quite some time what these secrets are, but it seems that the fans are keeping true to their word, posting a number of glowing reactions on Twitter that doesn't spoil anything for those who weren't at tonight's debut performance. With previews slated to run nearly two months before the official premiere, we'll have to wait and see if fans will continue to prevent spoilers from getting out on the Internet.

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Based on an original new story by J.K. Rowling, Jack Thorne and John Tiffany, Harry Potter and the Cursed Child is a new play by Jack Thorne, directed by John Tiffany. It will receive its world premiere in London's West End at the Palace Theatre this summer and is the eighth story in the Harry Potter series and the first official Harry Potter story to be presented on stage. Readers and moviegoers last saw Harry waving off his children at Platform Nine and Three-Quarters in Harry Potter and the Deathly Hallows - Part 2. Cursed Child will pick up the story, officially the eighth in the Harry Potter canon, after that moment.

It was always difficult being Harry Potter and it isn't much easier now that he is an overworked employee of the Ministry of Magic, a husband and father of three school-age children. While Harry grapples with a past that refuses to stay where it belongs, his youngest son Albus must struggle with the weight of a family legacy he never wanted. As past and present fuse ominously, both father and son learn the uncomfortable truth: sometimes, darkness comes from unexpected places. Take a look at the latest photos from Harry Potter and the Cursed Child, and stay tuned for more as we get closer to the start of previews on June 7, followed by the first official show on July 30 in London.

The rest of the cast includes Nicola Alexis, Helen Aluko, Jeremy Ang Jones, Rosemary Annabella, Annabel Baldwin, Jack Bennett, Paul Bentall, Anthony Boyle, Zoe Brough, Sam Clemmett, Morag Cross, Cristina Fray, Rudi Goodman, Claudia Grant, James Howard, Christiana Hutchings, Lowri James, Chris Jarman, Martin Johnston, Bili Keogh, Chipo Kureya, James Le Lacheur, Helena Lymbery, Tom Mackley, Barry McCarthy, Sandy McDade, Andrew McDonald, Adam McNamara, Poppy Miller, Tom Milligan, Jack North, Alex Price, Stuart Ramsay, Nuno Silva, Cherrelle Skeete, Esther Smith, Nathaniel Smith, Dylan Standen and Joshua Wyatt. Among these names are seven child actors who will alternate between roles. Take a look at these spoiler-free reactions and photos from the first preview performance for Harry Potter and the Cursed Child, and stay tuned for more on this highly-anticipated stage play.