Clad in an eye-popping print suit, his red hair gelled like a rock star’s, Grint makes a vivid comic impression as an arrogant critics’ darling, lamenting with a pout, “I can’t help it — I was born charismatic.”

“When I read the script, I loved the character immediately,” says Grint, who is much more low-key in conversation than “Sir” Frank. “He’s already been knighted and is on top of his game, but he’s sick of being glorified. He’s also a borderline kleptomaniac, bold and ridiculous and kind of crazy, which is really, really fun for me. The play has such a rich variety of characters, all wanting different things from the reviews.”

Soon after accepting the part during a Skype interview with director Jack O’Brien, Grint found himself in rehearsal with five legendary American stage stars. “On the first day, I thought, What have I gotten myself into?” he recalls with a laugh. “I was terrified, but everyone was really welcoming, and the audience response has been amazing.” Recalling a backstage visit with his Harry Potter costar Daniel Radcliffe during Radcliffe’s Broadway run of How to Succeed in Business Without Really Trying, Grint says, “Dan was just shaking with excitement, and I felt that I definitely wanted to have a go” at Broadway.