The classic tale of Dr. Jekyll and Mr. Hyde gets a modern revamping courtesy of BBC America. Their new dramatic series Jekyll features a modern day Dr. Jackman trying to contain his monstrous side. When the monster gets out, he takes on the name Hyde from the literary world and threatens Jackman's family. James Nesbitt plays both forms of the character.

Only two of Nesbitt's British films have crossed the pond with any level of recognition. The comedy Waking Ned Devine and the political drama Bloody Sunday made the art house circuits in 1999 and 2002 respectively. The Brits know him well from long running series like Murphy's Law. If Jekyll is his first introduction to many U.S. viewers, they will be treated to two unique performances.

"I think they're two entirely different characters that share the same skin so there was no crossover," said Nesbitt. "As the series develops, they connect a bit more but one was suppressed. One was human, one wasn't. Although you have to show the human side of both, [they are] two different characters."

Jackman is a successful doctor who constructs an elaborate containment system to lock himself in at night, when Hyde is likely to emerge. This puts a strain on his marriage, one that Nesbitt himself faces as an actor. "He has to walk away. Eventually when it becomes too powerful he has to walk away so he has to leave his wife and children without explanation. I do that in my own life. I'm an actor. I have to go away and it's awful for my children. Especially when they were younger. All kids think is, 'Well, do you love me? Why are you going?' You go, 'Well, I gotta go to work.' It's hard."

If the good doctor is a reflection of Nesbitt the working actor, the carefree Hyde comes from an earlier stage of life. "[For] Hyde I tapped into childhood because he's a child. So it was like remembering what it was to be a child and have no fear about showing off, but also a kind of malevolent child. So I drew on that."

Hyde can be witty as he's threatening his victims, but he is far from a class clown. The bad guys are always the most entertaining. "There are times when Hyde knows he's being funny but there are times where he's funny without knowing that he's funny. There are times when he's cruel when he means to be cruel. There are times when he's just cruel because he is cruel. So the question is just pitching the journey right."

One of Hyde’s lines in the first episode is telling Jackman's wife not to make any plans that involve walking straight. It is almost endearing, considering he is suggesting rape. "He knows he's being funny there. I love that. That's when I loved him. At one point he goes into a kind of southern American accent, but Hyde doesn't know why he says it. But it turns out that he loves watching Disney films and stuff so he must have heard that voice somewhere. Hyde picks things up, but from where he doesn't know."

Dr. Jackman has a sense of humor too, but one not based on the pain of others, and perhaps not as overt to audiences. "I think he's got strength. I think anyone that's strong has humor. I think that his humor is earned. For him to have come together with his wife, there were elements of humor within him."

To hear the actor discuss the two characters makes it sound like an easy matter of business. In fact, one performance is difficult enough. Imagine serving double duty. "In retrospect, it was an enormous amount of fun but when I was doing it, fun and hard work are muddied. I loved it but it was hard work. The words were so good, just trying to serve the words properly, creating two different characters, knowing exactly where you'd been, where you were going and saying the words. But ultimately exhilarating and satisfying."

If Nesbitt did his job right, audiences will truly sympathize with Jackman's plight and truly fear Hyde. In that respect, Hyde's acts of violence were some of the easier bits. He explains, "That was easy because that’s pretend. What's hard is to tap into the things that we have to believe. What was hard about Hyde was making the fantastical believable. What was hard about Jackman was you're representing a real person who is suffering lots and can't really express it. Those are precious moments because audiences are intelligent. You don't get it right, an audience will go, 'Oh, f*** you, I don't believe that.' No, you have to have an audience going, 'I believe you.' Otherwise they turn away."

Nesbitt came to the series with a full year of preparation. He did not do method training where he studied doctors or wild animals. His process was all internal. "I'm not Daniel Day Lewis, I don't skin rabbits, but I'm constantly thinking about it. I mean, I knew what I was going to do. You can't arrive on the first day of filming Jekylland think, 'Hmm, what'll I do?' I knew what I was going to do. The fear was, will it be okay? But I knew, I planned."

Getting into physical shape helped Nesbitt keep up his stamina too. Hyde may not be a bulky muscle bound monster, but that was not the purpose of the regimen. "I had a trainer for it but not only because training, getting fit, is not just about getting your body fit. It's about getting your mind fit. We didn't have huge physical changes between the two characters but a little did go a long way. I had to be fit physically not just to do what I was doing, but if I was fit physically, I was mentally fit as well. I sweated a lot, emotionally and physically."

Jekyll airs on BBC America on Saturdays at 9.