Meet the Harry Potter fans 'keeping the secrets' of the Cursed Child

You will know by now that the preview of part one of Harry Potter and the Cursed Child has taken place.

But we're guessing you don't want to know what happens in the long-awaited spin off.

We can tell you that the show ended with a standing ovation at the Palace Theatre in London's West End. And it was filled with surprises - magical surprises.

JK Rowling is urging fans to "keep the secrets".

This is why you have seen #KeepTheSecrets trending on social media.

Author JK Rowling had urged fans via her Twitter account to keep the surprises of the production to themselves so as not to spoil it for others.

Up until last night, fans didn't know what to expect, including what the set would look like.

We will tell you no more than that the story includes the difficult relationship between grown-up Harry and one of his children who is finding it difficult to deal with his fame.

The play is fast paced, funny, scary and moving at times.

There is plenty of familiar magic and characters from the much-loved franchise.

Throughout the performance there were gasps and cheers from fans at the many surprises.

Jack Maple described the show as "magical" in his tweet.

While Aislinn said "I just saw the best thing I've witnessed on stage," on her Twitter account.

After the show, the 1,500 members of the audience members were given badges saying "keep the secrets".

Leesha and Lisa, both 20, travelled together from Michigan in the US especially for the production.

"It was such an emotional experience, we are so glad that this is back in our lives. So many feelings," Leesha told Newsbeat.

"We thought they did a spectacular job, we really thought they translated magic well."

Both girls admitted to "sobbing" with happiness during the evening.

"I never thought that there would be new and more Harry Potter, now it's here," Lisa said.

Meanwhile, 20-year-old Emily Hadder told Newsbeat "they made the impossible possible".

"The magic and the fact that they could do that on stage.

"I don't think JK Rowling is writing about a magical world anymore, I think she's from it," said.

"I'm going to have to isolate myself, I think," Beth Taylor said, "and I think I am just going to have to tell people to go and see it."

Some fans came in Hogwarts colours, like 24-year-olds Kaytlen Keller and Mara Kiernan from Washington DC.

"It works, it's amazing.

"It's so much more than either of us thought it would be.

"I am so excited for the next one and I'm kind of shaking and I can't wait," Kaytlen told us.

"It flows perfectly with the books. It incorporates everything and I can't say anything. I'd love to share it, but I can't [give spoilers]," Mara added.

Colin Callender is one of the show's producers and told Newsbeat: "We are very pleased. It's wonderful to see it for the first time with fans who didn't know what was going to come.

"It is a preview, and the thing is until you actually see a play in front of an audience you don't know how certain things will work.

"People laugh at places you didn't think they would and they don't laugh in places you thought they might. You learn how an audience responds."

He says that they will fine tune the production over the next seven weeks.

He added: "We felt a real responsibility both to Jo [JK Rowling] but also to the fans to get it right.

"And we were conscious to do right by the fans."

Part two of the preview will be performed on Thursday.

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