LONDON (AP) – The curtain has risen on Harry Potter’s latest adventure – and J.K. Rowling is urging fans not to ruin the magic by letting its secrets out. “Harry Potter and the Cursed Child” has had its first preview at London’s Palace Theatre, with audience members given buttons urging them to #keepthesecret. In a recorded message, Rowling encouraged theatergoers to “let audiences enjoy ‘Cursed Child’ with all the surprises that we’ve built into the story.” The drama – staged as two plays – picks up the story 19 years after the climax of Rowling’s last Potter novel. Its characters include the adult Harry and his youngest son, Albus Severus Potter. The Daily Telegraph said Wednesday that audience members were “in raptures” after Tuesday’s performance.The plays officially open on July 30.