It's not exactly common to hear about injuries on film sets, but it's perhaps less common for one to make the final cut and then spawn a few fan theories. Speaking with GQ in one of their classic "_____ Breaks Down His Most Iconic Characters" videos, Split and Glass star James McAvoy revealed how he secretly broke his hand filming the 2016 M. Night Shyamalan movie and not only didn't know it at first but kept filming and even had his injury make it into the movie. The actor revealed in the interview that to get into character for a scene he would punch a door off camera, and though there was a padded area for him to hit he ended up punching the metal door and breaking two knucikles.
"I was meant to come in like, full of beans, and full of adrenaline. And the rest of the door was metal and I messed the pad a bit and I broke my hand," McAvoy revealed. "I carried on in the scene white as a ghost and kinda in shock. And Night came up to me like after that take and he was like, 'You okay? That scene was weird. That take was weird.' And I was like, 'Yeah, let's just go again.' I don't think I told him I broke my hand at that point. I didn't realize that I had broken my hand, I don't think. But it became quite clear within a few hours when my hand was like the size of a boxing glove. And it's actually a bit in the film where Dennis puts on his glasses and it's a profile shot and you can see my hand is swollen up. I've not seen this but I've been told by Night, that there was people sort of commenting online going like 'Oh he's turning into The Beast. He's turning into The beast." It was just me with my big, gamy punched up hand."
McAvoy adds that despite thinking his injury would heal itself, he ended up going to an urgent care on his last day in Philadelphia where he got the news about the severity of his injuries. The problem though? He had another job already booked for his next acting gig. He adds, I was like, 'Oh God.' I had to phone up the director of my next film and say, 'Listen, would it be okay if my character was wearing a plaster cast for the film?' And luckily it works for the character and I wore a plaster cast in the next movie because of that."
For the record, that next movie where he wears a cast the whole time? 2017's Atomic Blonde.