“Harry Potter and the Cursed Child” returned to Broadway, now in one part instead of two. It may feel smaller, but is no less dazzling.Like a lot of children, Harry Potter grew bigger as he got older. J.K. Rowling’s later novels in the series came in twice as thick, or more, as the first. The lengths of the film versions peaked with the adaptation of that final volume, “Harry Potter and the Deathly Hallows,” split into two parts running a combined four and a half hours. In 2018, “Harry Potter and the Cursed Child” — an original play by Jack Thorne, based on a story by Thorne, Rowling and John Tiffany — opened on Broadway at the lavishly remodeled Lyric Theater. Also split in two, the total experience clocked in at more than five hours.But now Harry seems to have shrunk. After a pandemic closure (and reported problems with production costs), “Cursed Child” has returned, shorter and more streamlined, its two parts collapsed into a single one and its length reduced by a third. The creators have kept quiet on the mechanics of this revision; call it “Harry Potter and the Mysterious Abridgment.” I assume someone pointed a wand at the published script and shouted, “Brevioso!”The new version, which opened on Tuesday, does feel smaller — its themes starker, its concession to fandom more blatant. But as directed by Tiffany and choreographed by Steven Hoggett, with an essential score from Imogen Heap, it remains diamond-sharp in its staging and dazzling in its visual imagination, as magical as any spell or potion.The essence of the plot hasn’t changed. “Cursed Child” still opens where the epilogue of “Deathly Hallows” leaves off, 19 years after the book’s climactic Battle of Hogwarts. On their way to that school of witchcraft and wizardry are Albus Potter (James Romney) — the second son of Harry Potter (Steve Haggard, in for James Snyder at the performance I attended) and Ginny Potter (Diane Davis) — and Rose Granger-Weasley (Nadia Brown), the daughter of Hermione Granger (Jenny Jules) and Ron Weasley (David Abeles).Aboard the Hogwarts Express, Albus meets Scorpius Malfoy (Brady Dalton Richards), the son of Harry’s former nemesis Draco Malfoy (Aaron Bartz), who offers him sweets. Albus and Scorpius’s burgeoning friendship upsets both of their fathers, complicating already fraught relationships and imperiling the entire wizarding world. Because what is Harry Potter without a threatened apocalypse and the occasional chocolate frog?Richards, left, as Scorpius Malfoy with a Dementor in “Harry Potter and the Cursed Child.”Sara Krulwich/The New York TimesThe audience experience begins long before the lights go down, through the sumptuous lobby and into the auditorium. Every carpet, curtain, light fixture and wallpaper strip helps to immerse you into the Potterverse. It’s a marvel of imagination, and more shows should think about extending design beyond the stage. Even the reminder to wear a mask is presented as a boarding announcement for the Hogwarts Express.In the opening moments, that train seems to have been refitted as a high-speed rail. Everyone moved and spoke so fast — Jules and Richards were almost unintelligible — I was briefly worried that this new version was simply the old one played at 1.5 times speed. I once counted two consecutive seconds in which nothing happened onstage. Once only.Yet there are excisions, most of them so surgical you would never notice, though I did slightly miss the beloved Hogwarts groundskeeper Hagrid. Other changes are more pointed, like the rendering of Albus and Scorpius’s relationship as explicitly romantic, which has a knock-on effect of flattening the father-son conflict. Gone too are the dream sequences that bolstered the play’s mournful tenor and provided much of its exposition.Steve Haggard, left, as Harry Potter and James Romney as Albus Potter.Sara Krulwich/The New York TimesWith a lot of that context missing, the show is now more difficult to recommend to anyone not already versed in Potteralia. (Surely there must be someone left?) The most audible reaction I heard came when a character announced herself as Dolores Umbridge, a revelation that means nothing without knowledge of the books and films. Luckily, I had brought along my daughter, an 8-year-old who has made her own butterbeer and strongly identifies as a Gryffindor.At intermission, she turned to me, eyes bright and round as golden snitches. “This movie has great special effects!” she said. She often calls plays movies, a beautiful way to troll her theater critic mother. Still, I couldn’t entirely disagree. The original “Cursed Child,” with its luxuriant running time and hyperfocus — for better and worse — on the emotional lives of its characters, felt explicitly theatrical, the wresting of a real work of dramatic art from a massively popular franchise. This new version remains ravishingly entertaining, but is also, like the movie adaptations, a more obvious attempt to cash in on Pottermania.Yet there are loads of films — even those with the extravagant C.G.I. budgets of the “Harry Potter” movies — that come nowhere near approaching the magic of Tiffany’s staging, enhanced by Christine Jones’s set, Katrina Lindsay’s costumes, Neil Austin’s lighting and Gareth Fry’s sound. Jamie Harrison’s illusions, the stuff of phoenix feather and unicorn horn, are an absolute astonishment. (Were fire marshals ensorcelled into approving this show’s pyrotechnics?) During the sped-up beginning, I wondered, darkly, if the show could now exist as just another theme park attraction. It’s more than that. Besides, three and a half hours of enchantment is still a hell of a ride.Harry Potter and the Cursed ChildAt the Lyric Theater, Manhattan; harrypottertheplay.com. Running time: 3 hours 30 minutes. More