Something highly unusual is happening Saturday night, July 30. And if you play your cards right, you could be a part of the reason why. The creative minds at Chop Suey Books will celebrate the birthday of the world’s favorite fictional wizard, Harry Potter, and the release of “Harry Potter and the Cursed Child, Parts I & II,” with the first official, unauthorized performance of the hotly anticipated book at the Byrd Theatre. The performers will be chosen from among the new owners of the book. Choosing on a first-buy, first-cast basis, the people who buy the book can pick their roles in the production. If you miss out on the first act, don’t worry — actors will be replaced after a couple of pages. Doors open for the strange magic at 11:30 p.m. Call 422-8066 or visit chopsueybooks.com for clues.