Filming “The Power of the Dog” was a very particular type of challenge for star Benedict Cumberbatch. Not only did he need to portray an accomplished rancher, who is an excellent carpenter, whistler and can tightly roll a cigarette with one hand, but the actor also had to pick up the banjo for the role.

“I’ve yet to master but the banjo,” Cumberbatch quipped, in conversation about “The Power of the Dog” at Variety’s TIFF Studio.

“If you put an instrument that takes years to practice in someone’s hands who’s had one year, or a few months in my case, there is nothing like pulling you out of an authentic experience, committing to something you believe is immersive and going, ‘Oh this is such a fake moment,'” he said, with a laugh. “It’s really painful.”

All joking aside, the project was a deeply affecting experience for both the Oscar-nominee and his co-star, Kodi Smit-McPhee, who found themselves totally immersed in Jane Campion’s adaptation of Thomas Savage’s classic novel, which discusses the ills of bias and intolerance and dissects the phenomenon of toxic masculinity.

Cumberbatch stars as Phil Burbank — a macho rancher, who is repressing his inner feelings and desires, while outwardly tormenting his brother George’s (Jesse Plemons) new wife Rose (Kirsten Dunst) and her son Peter (Smit-McPhee). Cumberbatch sees Phil as a tragic figure. “He’s a man in great pain. He’s so lost in his masculinity, in his veneer of masculinity,” the actor shared, explaining why he was drawn to Phil’s story.

Whereas Phil is haunted by who he is, Smit-McPhee was drawn to Peter because the character is so comfortable with himself.

“[Playing Peter] gave me an opportunity to own myself and own the things that maybe are not accepted in society that I’ve experienced myself, and which he completely does,” Smit-McPhee says. “He taught me that we don’t all necessarily have to fit in a box and that’s okay, and we can be confident about that.”

After coming of age on screen, Smit-McPhee says that he can relate to the movie’s meditation on personal acceptance.

“I’m a very feminine guy and that’s something that I really confidently embrace in my life and I think it gives way to a lot of my artistic side and my creativity,” Smit-McPhee explained. “And throughout the industry, being in front of many eyes and throughout school, it’s something that I’ve had to learn to embrace and love about myself and the need to change that. I saw that reflected in Peter in different ways.”

The duo also detailed their experience working with Campion, the Oscar-winning filmmaker who picked up the Silver Lion best director prize at the Venice Film Festival just hours after sitting down with Variety.

“She’s a real alchemist, isn’t she? She knows how to create an environment through very open means, but they do deviate from the norms,” Cumberbatch said.

For example, Campion had Cumberbatch and Plemons waltz for rehearsal in an effort to help them find that brotherly love. But they found that the unconventional created real chemistry. “It gives you real courage to be daring, to leave yourself vulnerable and exposed and be fully prepared to give her everything,” he said.

It’s not like Cumberbatch and Smit-McPhee aren’t used to doing somewhat strange things to get into character. In addition to the litany of dramatic works on their resumes, both actors are also superheroes — with Smit-McPhee playing Nightcrawler in “X-Men: Apocalypse,” “Dark Phoenix” and “Deadpool 2,” while Cumberbatch has starred as Marvel’s Doctor Strange since 2016.

“They’re such different asks, it feels like a completely different musculature,” Cumberbatch explained, reflecting on the privilege of playing in both genres. “Of course, that you’re still trying to get something that’s authentic and committed no matter what the scale of it, whether you’re acting with a great actor, or a ping pong ball that’s supposed to be some weird creature, it’s all imagination and commitment.”

In some ways, the working methods are different. “The Power of the Dog” had “a sort of cannon of importance with the script that’s sort of solidified before you go into shooting,” Cumberbatch explained. “You often go into production with only two thirds of the script on these bigger sand pit play pens, and there’s a looseness about that that’s sort of terrifying.”

But on the other hand, Campion’s openness as a filmmaker required a similar element of trusting the process. “And equally, you have a hugely passionate audience waiting for the adaption,” Smit-McPhee noted.

“There’ll be an intense literary audience that will know that book. And hopefully, a cinema audience waiting for Jane’s next work who will go, ‘I really want to read that book too,'” Cumberbatch agreed, with a laugh comparing the fervor of the book fans with the intensity of their comic book experiences. “Much bigger with the Hall H crowd, that expectation.”

So, could there be any potential for a crossover with Smit-McPhee returning to his “X-Men” character now that the IP is part of the MCU?

“We’ve talked about this,” Cumberbatch said. “We loved working with each other, so we would love to do that jam. Of course it’d be a very different vibe, but yeah.”

“It would be so cool,” Smit-McPhee chimed in. “It’s an honor to play both sides of the spectrum, but it would be even more an honor to to cross paths again with someone you grew so close with on something so theatrical, something like this, and then to go to something fun like that — it would be great.”

“The Power of the Dog” debuts in select theaters in November and begins streaming on Netflix on Dec. 1.