When it came to wearing a mask, Ethan Hawke was wise enough to observe that masks have been used in acting going back to the times of ancient Greece. In Greek theater traditions, stock characters would be recognized by their masks and would often be accompanied by a chorus of other masked players. This was a new opportunity to mature as an actor and delve into physical acting Hawke had been utterly uninterested in as a younger man. He told Entertainment Weekly:

“Scott [Derrickson] wanted me to do a part in a mask for an entire film, and all of a sudden I feel like I’m doing Greek drama; he allowed me to give a performance in the middle of a horror movie … [T]hings that I was bored senseless by when I was 18 and now see as keys to making this profession interesting to me for the next 25 years.”

So the mask was not necessarily antithetical to acting. But for further diffusion of his anxiety, Hawke also took a great deal of comfort from a particular Bob Dylan lyric:

“There’s a great Bob Dylan line in that Scorsese doc [‘Rolling Thunder Revue‘] where he says that if somebody’s got a mask on, you know they’re telling the truth, and if they don’t have a mask on, you know they’re lying. That was on top of my brain; the scariest thing about [my character] is that he doesn’t want you to see him.”

Derrickson took a risk in asking Hawke to play the part; he knew Hawke had a stated aversion to playing villains. In an interview with SyFy Wire, however, Derrickson recalls receiving an utterly creepy voicemail from Hawke as the actor’s way of accepting the part: 

“I sent him the script anyway and that night he left me a voicemail in this menacing voice, and he said, ‘I’m gonna murder the f*** out of you … It’s gonna hurt really, really bad.’ It was a line in the script, and that was how he was letting me know he was going to do it.”