In NBC’s Aquarius, Gethin Anthony plays an eerily charming version of the infamous Charles Manson that makes us understand why some people found him irresistible. His fine performance modulates Manson’s explosive personality through subtle, seductive touches; a bravura work of acting that might come as a surprise for those who only know Anthony’s work from Game of Thrones, where he played the too noble Renly Baratheon. The Oxford graduate has an extensive theatre background, and has also appeared in iconic BBC television shows like Call the Midwife and Doctors. With Aquarius showing his impressive range, it should only be a matter of time before he becomes a household name. With the NBC show, where he acts opposite David Duchovny, about to be released on DVD and Blu-ray we talked to Gethin about his turn as Manson, his personal ways of consuming television, rumors of his extraordinary dance skills, and inevitably we found our way talking Sondheim.

As an actor coming from an immensely popular property and then playing an iconic character like Charles Manson, were you intimidated or insecure in any way thinking people would perceive the show as Special Agent Mulder chasing after Renly Baratheon?

(Laughs) As far as being an actor, you can’t ignore the opportunity that’s in front of you and I’ve been very, very lucky to work with some great people. I was lucky to talk to the people in Aquarius about how they were going to do it, how they were going to do it, and they gave me the confidence. It was a huge opportunity and I jumped into it with both feet.

Did you find it necessary to try to find any redeeming qualities in Charlie?

It’s not about that really, it was more about understanding him and his life experience up until 1967 when the story takes place. Then it was about trying to understand each scene as it comes up in the story by virtue of inhabiting the character as best you can. I never really had to stand back and ask myself if I liked him or not. I think that also helps you keep your own sanity.

I read that at some point someone from the crew brought in a shaman to bless the place where you were shooting. Considering how much the figurative ghost of Charles Manson haunts Los Angeles, how did this affect your work?

I don’t know if I’d use those words (laughs), seriously though, just to be in LA and understand the significance of the story and how so many people who were alive back then are still alive and were being affected by it, helps you be sensitive to how you’re doing what you’re doing. Then, the simpler thing of the shaman was a sweet thing, someone thought we were dealing with a tricky subject matter, so we started it right by have the shaman dispel any negative energy, something that I’d never done before. It was a very pleasant experience and I’m doubly grateful because I missed the first day, so they brought him back the day I started.

I’m sure that you did a fair amount of research to play the part, and I’m really curious, now that you know more about Los Angeles history and how the Manson murders changed Hollywood, did you detect anything new that you hadn’t noticed about films of the era that you thought you knew well enough already?

That’s a fucking good question (laughs) and I haven't looked at it in that angle before, it’s so interesting. I’m now desperate to go watch them all again to see if I see anything different. I know that in a wider sense, the crimes extend to the hippie movement going into a remission at the end of the 60s, not only because of the crimes, but because there was a change in the environment and how people treated each other. I’m sure things done in the early 70s reflect that, I’m gonna go back and watch some movies after this, write down stuff in my notebook.

It’s strange to think that without Manson’s disciples murdering Sharon Tate there would be no Chinatown for instance. I find this even more interesting because Manson felt that the entertainment industry owed him something, because he was denied a recording career.

Working on the show, the most immediate thing to concentrate on was being frustrated and what that frustration and energy could do to your decision making. I think you have to limit yourself to the parameters of the stories you’re telling and not get too lost in it, there are definitely moments in telling this story that were difficult for me to confront on a personal basis, and you sort of do that by leaving set and at the end of the shoot reconnecting with your family and friends.

Have you listened to Karina Longworth’s You Must Remember This podcast, which covered the Manson murders? It’s one of the scariest things I’ve found recently and you’ve mentioned that you became fascinated with a 1967 voice recording of Charlie, so can you comment on how sound helped you find this character?

It’s helpful for me personally on a number of levels, I have a background in theatre in the UK, which is a very normal route for many British actors because we’re doing plays in school and things like that. Oratory, pitch and how you use your voice are very important, so seeing what I could do with my voice to play him was essential. There is one clip of him speaking to a studio engineer that was helpful not only for the rhythm of his voice, but also because of the things he was talking about, which connected to the dialogue the writers wrote for him in the show. The clip was the beginning of the process of inhabiting him, by learning it like a monologue and doing it over and over. It was a very useful first step.

Charlie was notoriously also a terrible singer, but you’re a tenor. Other than having done The Sound of Music as a kid, are you interested at all in musicals?

I sadly am actually (laughs) the truth is I’m a little bit out of practice, but I’m a huge Sondheim fan and I have to be honest with myself and say that if I ever get to do a musical I have a lot of work to do first, and train for a while.

Now you have to tell me your Sondheim dream parts!

You know I’m going to say Assassins (laughs).

You also have African dancing skills. Maybe you can do The Lion King! Or Hair?

Yeah, let’s talk about that…that’s not the most accurate story about me out there (laughs). I’m not trained in African dance, I did a community project with a wonderful Nigerian troupe when I was 14, but we weren’t “trained”.

By the time this interview is out, Aquarius will be out on DVD as well, not to mention NBC made it available to stream. What’s your preferred way of watching a TV show?

For me personally it depends on the show. Some things I watch live on TV, but I also have a habit of saving things and just binging them four episodes at a time, it’s been a while I’ve been able to watch something like 13 episodes in a row, so I’m impressed by people who can do that. A good example would be Game of Thrones, I back them up a bit, and watch three episodes at a time which makes them like little films.

I happened to catch Copenhagen in which you were great, are you doing any more indie film work? This movie made me think a lot of Harold and Maude in its tone.

Oh wow, thanks, I’ll tell Mark Raso you said that, it’s an interesting connection. I keep pushing him for us to do two sequels to that, it’d be great to do Copenhagen 2 with a better title obviously. Part of the excitement of that was telling a story in under two hours.

Back to TV, Aquarius also has a web series which compliments the story, so I’m curious about how you feel about the idea of shows being so immersive nowadays?

Well...I remember when I watched The Wire I watched all seasons in a few weeks. All I could do was talk about those people, I would tell my friends “you have no idea what’s going on with Omar”, or Bubbles really, he’s actually the one I worried about the most.

Now, the most important TV question of our times: to spoil or not to spoil?

We live in a really instant time, there was a time when there would’ve never been a thing like spoilers, but now after big moments on TV I avoid my Facebook. I tend not to post spoilers about anything, but it’s tricky in this job, when I finished Game of Thrones, I’d go into casting rooms and assistants would be like “wait, so you’re available?” (Laughs) It’s hard to avoid them!

Aquarius will be available on DVD and Blu-ray on September 15.