Walking out of London’s West End Trafalgar Studios, 33-year-old Scottish actor James McAvoy looks weary. He should be. Playing one of Shakespeare’s supreme villains in Jamie Lloyd’s production of Macbeth, he’s spent the last two hours pouring every drop of evil he can find into the iconic role.

But in the midst of his visible exhaustion, he’s polite—anxious to discuss the role that he quickly admits he’s been “dreaming of playing” since he was 24.

As with any of Shakespeare's leads, the role has not been easy.

Documented on news channels across the UK, the physical nature of the production has taken its toll on the actors, McAvoy included. “We’re getting used to it,” he laughs, when I broach the topic.

Lifting his swollen hands and visibly cut-up wrists as proof, he leads me through a trail of wounds. “That’s a new one. That’s a new one,” he says, pointing to scratches and cuts. “That one finally healed!” he smiles. McAvoy says many of the wounds are due to “trapped nails” on the set, others simply the result of the method acting they’re using on stage. After catching my uneasiness at the blood caked under his fingernails he blurts out (in a thicker-than-usual Scottish accent), “This is fake blood! I can’t get it out of my f—king nails.”

If it’s making the audience squirm, as I just have, McAvoy says he’s doing his job. When asked about the inordinate amount of spit he spews wildly throughout the performance, he’s noticeably flattered. “Well, I’m a very shouty MacBeth! You know you’ve got the audience there and anything you can do to make them feel uncomfortable...we do it on purpose… to make people feel like...fuck, fuck, fuck.”

Mission accomplished. Fueled by Macbeth’s childlessness, the play is as brutal as the script allows. With blood gushing from the ceiling, sharp swords flailing, and loud physical contact, the audiences's repeated cringeworthy looks were telling: McAvoy puts on a gruesome affair. “Macbeth is a very violent play in its text, and the director [Jamie Lloyd] thought that it should be as physical—even if not at times violent—it should be as physical as possible,” he explains.

Although he doesn’t mention whether or not he and his wife of seven years, Ann-Marie Duff, are planning to add to their small brood, he insists that playing the role as a young man, “who should be having kids now,” is key. It was this close connection to childlessness, he says, that allowed him to connect deeply to the role. “When [Macbeth] envisions the end of the world, when he envisions his doom, there are always children in the portrait.” McAvoy cites this as the reason he "kills all the little babes."

The scenes in which the children are murdered are particularly brutal to watch—and listen to, as Macduff’s young son shrieks through his own slaying. Still, McAvoy insists it’s those very scenes that form the backbone of the protagonist’s evilness, and ultimately, his insanity. “I thought as a 60-year-old or even 50-year-old man, I’d expect, someday—as tragic as it is—the childlessness, that you’d have gotten over it.”

It’s impossible to ignore McAvoy's genuine dedication to the tale of Macbeth, and his pivotal role in delivering it. “Was the story clear? Honestly?” he asks me. The question doesn’t need an answer.

Editor's Note: An earlier version of this story wrongly implied that James McAvoy is childless. He and his wife welcomed a son, Brendan, in 2010.