From director Toby Haynes and screenwriter James Graham, the biographical drama Brexit (airing on HBO and available on HBO NOW, HBO GO and HBO On-Demand) connects all of the dots to illustrate how Dominic Cummings (Benedict Cumberbatch), the lead strategist of the Vote Leave campaign, launched a micro-targeted social media campaign that played on emotion rather than facts to convince British voters to leave the European Union. The result and the consequences of this referendum campaign are still playing out in Britain today, and will have an effect long into the future.

During this 1-on-1 phone interview with Collider, actor Benedict Cumberbatch talked about his shocking appearance in the film, how his friends and family reacted to his hairline for the shoot, why he wanted to be a part of this project, using wit and humor to tell a gut-punching and dramatic story, the shorthand he’s established with director Toby Haynes (Sherlock), why it was important to him to work from within the point of view of Dominic Cummings, watching the effects of this vote still playing out in real time, and the embarrassment of riches he had in his career in 2018.

Collider: Thanks so much for talking to me about Brexit and your performance in it, from wherever you’re currently shooting.

BENEDICT CUMBERBATCH: I’m in Prague. I’m doing a night shoot, so I haven’t started my working day. I think I start about 10:30 until 7:30 in the morning. I’m just gearing up to have fun. It’s minus 7 here, and it will probably actually get to minus 10 later, so that’s going to be fun.

I have to say that it’s amazing how just some tweaks of a hairline can drastically alter someone’s appearance, to the point when you first come onscreen in the film, I gasped out loud.

CUMBERBATCH: If you want to go about your daily life and not be recognized, I thoroughly recommend having a “no-hawk,” which is what I had and the opposite of a mohawk. You gasped. I had to wear a hat for the duration of the film, which was literally glued to my head when I wasn’t on set. I’ve got this amazing photograph album, where I’d take the hat off and I’d take a photograph of friends and family who I saw over that time, including on my birthday, and it was just a wonderful picture of shock, dismay, horror and confusion. It’s the most wonderful array of human reactions. It’s great.

What was your own reaction to seeing yourself like that?

CUMBERBATCH: I was like, “Well, good, we’re half-way there to looking like him.” I needed to have a good wig on top, to mark out where the hair was being scraped over and where it was going. Once I had done that and the contact lenses, I was happy. I was looking a lit bit more like someone who looks remarkably different to me, even though he’s not that well known to the public. People said, “We’ve cast you, we haven’t cast him. It’s fine. You don’t have to look like him.” And I said, “I think being me, I do have to. I want to step into this person’s skin. I want to feel and look like him. I want to think like him and move like him, and this is part of it. So, I’m gonna do this.” They were like, “Are you sure?” And I said, “Yeah, I really am sure. I have to do it.” But, I’m thrilled with the result.

When the possibility and opportunity to play this guy came your way, was it one of those things where you were immediately on board, or did you need convincing to play him?

CUMBERBATCH: I didn’t need much convincing ‘cause I’m a huge fan of James Graham’s work from his previous stage work. It’s like a thriller. And I thought this guy is intriguing, smart, cantankerous and brave, but he’s also human. He doesn’t want to get involved with this fight that he feels strongly about because of the people involved. And the people involved, when he does get involved, try to get him uninvolved. This drama is telescoping from his very subjective way into it, with the monologue at the beginning, into his campaign and the people who run it, into the opposing campaign, into the nation at large, and that amazing test group scene. All of that was done with wit and humor, at an entertaining pace and rhythm, and it was a really dramatic, and, at times, emotional, gut-punching drama. I was intrigued by the read of it, and then I talked to James about him, about him as a character, about how he sourced the stories and the points of view, and all the characters. I said, “I really wanna do this. Can we just try to make the timing work?” And my agent was really on board with it because of how good the script was. So, that’s how I came to be involved.

And you had previously worked with the director, Toby Haynes, on Sherlock. Was he already attached to it, as well, or did you think he would make a good fit for this?

CUMBERBATCH: I think Toby was attached. I didn’t produce this, so I didn’t have a say in that. Toby was already very much that guy. I can’t remember who was first in getting into things – whether it was Toby attached first and then me, or vice versa – but he was definitely another draw. I definitely talked to him about what kind of film he wanted to make, out of this incredible story and script, and what the final piece would be. We’ve danced together a couple of times, in our other projects, ‘cause we enjoyed working with each other so much on Sherlock. It was a great fit for both of us. That was another huge benefit to doing this.

What do you like about working and collaborating with him? Is there just an easiness, when you know how somebody works?

CUMBERBATCH: Yeah, you have a shorthand. He wears his heart on his sleeve. He’s very transparent, as a human being. There’s a friendship there, as well. It’s not just a working relationship of respect, but there’s also friendship of support. The shorthand is the biggest thing. I also knew that he was gonna take this into the realm of not being just a drama of men talking in a room. Especially with Danny Cohen’s cinematography, I knew it was gonna have a visual impact and a style to it, and that there would be an editing, coloring and score flavor that would give it something other than just what it is on the page, which was pretty spectacular. So, I was confident that it would be really good with him at the helm, as well as I would have a good time making it with him.