Wicked: The movie’s best moment shows the problem with the rest.

Nearly two hours into the extravagantly overstuffed Wicked: Part I, two familiar faces show up on the streets of the Emerald City. In the middle of the Glinda–Elphaba duet “One Short Day,” a theater troupe puts on a little history pageant telling the story of the Wizard’s arrival in Oz. In Elphaba and Glinda’s dialogue scenes, which in the musical’s first half are rich with comic moments and prickly exchanges, Chu mostly avoids two-shots, cutting back and forth from one witch to the other, showcasing each of his stars in turn but withholding the reactions and interactions from which an onstage relationship is made. It’s a two-minute master class in showmanship, a skill Chu has in spades but which his two leading ladies haven’t quite mastered—in part, it must be said, because Chu’s razzle-dazzle often out-razzles theirs. There’s still, presumably, another three hours or so of Wicked to go, and though the second half of the musical is a whole lot grimmer than the first, I hope Chu notices what a ray of sunshine this cameo duet really provides—and steps back, just a bit, to let his two talented lead actors really perform.