“I think there were a lot of things that the script asked that I have never seen her do, so I was trying to figure out how we were going to get there,” Aronofsky, 48, explained in an interview with Vulture. “And during the rehearsals, she was very, very relaxed. She was present… I really didn’t get to know the character until we started shooting, and she showed up."
"During the big climax of the movie…She really went there," he added. "The producers were freaking out. We had to sort of calm it down and then go for it again. And the thing is, there’s so much ability there that somehow she can summon it again and again."