Adapted from Diana Gabaldon’s international best-selling books, the Starz series Outlander spans the genres of romance, science fiction, history and adventure, all in one epic tale. The story follows Claire Randall (Caitroina Balfe), a married combat nurse from 1945, who is mysteriously swept back in time to 1743, where she is immediately thrown into an unknown world that is threatening and dangerous. Once there, she meets a chivalrous and romantic young Scottish warrior, named Jamie Fraser (Sam Heughan), and they are undeniably drawn to each other.

During this exclusive interview with Collider, executive producer Ronald D. Moore (Battlestar Galactica) talked about how he ended up bringing this story to TV, creating its world, making the show for fans of the book and trusting that viewers that aren’t familiar with it will get sucked into the show, how closely they’re working with author Diana Gabaldon (who even has a cameo in the season), having the freedom to change things around or expand on certain things in the background, the challenge of finding the perfect cast, deciding on 16 episodes, that the first season ends pretty much like the book does, and how he likes interacting with fans. Check out what he had to say after the jump, and be aware that there are some spoilers.

Collider: How did you come to this?

RONALD D. MOORE: As Battlestar Galactica was winding down, I was having dinner in Vancouver with my wife, Terry, and my producing partner, Maril [Davis]. We were just talking about future projects and things we all loved, and it turned out that the two of them, independently, loved these books and never talked about it. They started to get excited and talk about how great Outlander could be, but I hadn’t read it. So, they had me go off and read it, and I just saw it, immediately. I love history and I like historical fiction, so I was pulled into the period. I really like the central character of Claire. So, by the time I got to the end of the book, I thought, “Okay, yeah, this is a series. I can see how these episodes lay out, over a season.” There were eight books, at that point, so that’s many seasons. I was sold. I have always wanted to do a period piece, and I could do two period pieces, with the 1940s and the 18th century.

When you read this, did you think it would be easily filmable, or did you have to figure out how to do that, after the fact?

MOORE: I always had hubris enough to believe that we could figure out a way to shoot it. I knew we could go to Scotland and shoot it. In a lot of ways, it’s not that much different than what I did with Battlestar and Star Trek, in that I’m creating a world that doesn’t exist. You can’t just go out in the street and shoot a scene, or just rent clothes for any of these projects. I’m used to something where you have to create an entire world, and I do like that process. I like getting the audience to believe that outside of the frame of your television set, there’s a whole real world that exists, that is different from your day-to-day reality. I like that. That excites me, as part of the project.

Are you approaching this as if everyone watching it has never read the book?

MOORE: We don’t tailor it for the non-fan. Starz, from the get-go, said to make it for the fans of the book. They said, “Trust the book. We trust the book. And trust that anyone who samples it and does not know the material will just get pulled into the story.” So, that’s our philosophy. We just trust this story, so come along with us for the ride. If you know where it’s going and you’ve read the book, you’re going to have one experience. But if you come to this project, not knowing much about it and you just turn it on, it’s a compelling story. Here’s this woman who’s thrown back in time. Suddenly, she’s with these highlanders. She wants to get home to her husband, who you’ve met in the opening frame. Here’s this 18th century world with danger, romance and violence. What’s going to happen to her? It’s just an interesting story.

Was it important to you that this is not a story about time travel?

MOORE: Yeah, I was glad that that’s not really the show, at its heart. It’s the catalyst for everything that happens, but it’s really not about that. It’s about love and loyalty and trust and obligation. It’s more eternal themes than it is really about time travel. It’s not about different timelines, or if you change the past, how will it affect the future. Even though those questions do come up, periodically, it’s not the central focus of the story. It becomes a more overt science fiction piece, once you really get into intense discussions of timelines and how one event can be like dominoes through history. That plays through certain elements of the show, but not very strongly, especially not in the first season, because you’re just with her. It’s her story, and she doesn’t care about any of that. She just wants to get home, and that’s the audience’s point of view. We only care what she cares about, and she’s just trying to survive, not get caught, and get back to her husband. And then, she falls in love with this other man, which creates a conflict, and what is she going to do? She really doesn’t belong here, and she really does love Frank, but she’s falling in love with Jamie. That’s an interesting place to be.

It’s just such an inherently tragic story, since Claire doesn’t know if she’ll ever get home.

MOORE: Yeah, it is. There are definitely elements of tragedy and melancholy of what’s happening to her and what might happen to her. I guess that’s part of why people call it a romance. Romance classically has tragic underpinnings to it.

How closely are you working with author Diana Gabaldon?

MOORE: Before we even pitched it to Starz, I went to Scottsdale with Maril and we spent a weekend with Diana, just talking over the story and adaptation and how it would work. I told her how I wanted to approach it, and some of the things that I thought I would change from the book, and she was very open to it. She got it, from the beginning. She said, “I get it. It’s an adaptation. It cannot be literally the page. I don’t do television. I’m an author. You do that. Let’s talk about what you think would change.” She was very open. We’ve given her scripts, and she reads scripts and gives us comments on them. Basically, she’s really enjoyed and liked all of the things we’ve done, which has given us tremendous confidence in the fan response. She’s the queen, and the queen likes it, so we’re hoping that the rest of the followers like it, too.

How did her cameo come about?

MOORE: That was our idea. We just said, “We’ve gotta do this.” Why not? It’s her world and her story, so she should have a moment of being in it. She’s seen a lot of the footage and loved it, and she’s been very thrilled. She’s been very, very supportive. It’s been a remarkably positive relationship with her. Especially after having seen Saving Mr. Banks, I was like, “Wow, this could have been much worse!”

Now that you’ve established a relationship with Diana Gabaldon, do you feel more constricted, knowing that she’s reading the scripts, or do you feel a real freedom to change what you feel needs changing?

MOORE: I don’t want to just keep puffing it and making it sound like it’s so great, but it really had been great. She’s been very open to it. I’ve always said, from the very beginning, that I wanted to make it as faithful to the book as I could. And Starz said, “Make it faithful to the books.” That was always the goal. And then, you put the cards up in the room with the writers, and you start with the book version of events and the book scenes, and they don’t always work in an hour. The book was not designed to be adapted. So, you’re taking something that was written for a different form, and now you’re translating it and you have to figure out what works in an hour episode. You have to ask, “How does it gather shape? What’s the arc in this episode? Where are we starting and beginning?” There’s a scene with Claire where they’re on the road and, suddenly, she ends up in the hands of Jack Randall, and there’s a great scene between the two of them when he punches her in the stomach. It’s a really great scene, but when you look at the book, it’s not that many pages. It’s just a few pages. But we said, “That should be a full episode. We should make something bigger out of that.” So, in some instances, you’re taking what’s there and you’re actually expanding it. Other times, you skip over something. Sometimes you move the chronology slightly because you couldn’t quite figure out how to get from A to B in this order, so you re-sequence it and keep going. You’re constantly juggling the particular constraints of what you’re doing for episodic television, but you’re always getting back to where the book is taking you.

Did that affect the way you developed certain characters, as well?

MOORE: There’s a character named Rupert, who’s one of the highlanders, that we gave a bigger, more prominent role. There’s another character named Angus, who we changed and made more of a friend to Rupert. We boosted up their roles, as our core group of highlanders that you come to know. I don’t think we lost any major characters. All of the characters from the book that you would remember are present in the story. And I don’t think we combined anybody.

Did you look at any of the online talk about what scenes or what moments that fans felt were the most important in this story?

MOORE: Not so much. My wife is the #1 fan, so it was easy to check because I could literally turn to her and say, “Do you remember this? What’s important to you?” Maril is also a hardcore fan. I always had them as a resource. And then, I had myself, as a reader, and what I took away from the material, as far as the big moments and the tentpole scenes that you had to have, and where there was room for interpretation. Some things we filled in that were implied or could have happened. One of the first things I pitched to Diana was opening the show in World War II, with Claire in a field hospital in France and seeing her as a nurse. There’s not a scene written like that in the book, but clearly that’s her backstory and she refers to experiences. It was certainly part of the story, so we decided to open there. I wanted to set that up to tell the audience who she is and what her skill set is, and to immediately pull you into this tale.

How many times did your wife say to you, “No, you can’t do that! You can’t change that!,” but you did it anyway?

MOORE: Several times. I have to trust my instinct. I started my career at Star Trek, and that had a huge, very vocal fan base. I quickly realized that I was a fan of Star Trek, but it wasn’t a democracy. I had to go with what I thought was good. I did the same thing on Galactica. I have to believe in it and trust my instinct on what I’m trying to do, and then hope that other people agree.

How difficult was it to cast this show?

MOORE: I think we have a great, amazing, solid cast. At the beginning, I said to everyone who would listen, “We’ll cast Claire quickly. She’s a modern character and there’s a lot of great British actresses out there. We’ll find somebody right away. Jamie will be the one that will kill us. We’ll cast him the day before we shoot because he’s the king of men.” That’s what we call him in the writers room. He’s this heroic figure that’s built up in the fans’ minds, so who could be that guy? I thought that would take us forever. Of course, it was the exact opposite. Sam [Heughan] was the first one we cast. His audition tape came in and we just all looked at each other and went, “Oh, my god, that’s him! That’s Jamie, right there!” We sent it to Diana and she had the same reaction, and suddenly we had a Jamie. And then, Claire took forever. We saw lots and lots of actresses. It was a surprisingly hard role to cast. You really have to have somebody special. It’s her story. The show lives and dies on Claire. She’s in every scene and she’s talking in voice-over. You’re watching her think and you’re in her head a lot. You’ve really gotta have the right person, and it took a long time. We saw a lot of great actress. And then, we saw Caitroina Balfe’s tape and it was the same thing. We just said, “Oh, my god, there she is!”

Was it important that the actress playing Claire not be so familiar to people, so that they could easily get lost in the story?

MOORE: We talked about it. I thought that was gonna help, certainly. It didn’t preclude the possibility of casting a more recognizable person, but we all felt, instinctively, that if it was someone that the audience was less familiar with, it would help, for that very reason. You could just accept them as this character, and not think of other characters you had seen.

Every time you made a casting announcement, did everybody have an opinion?

MOORE: Oh, yeah, of course they did! The crazy thing on this project was that, before we even announced that we were doing the series, if you went on YouTube, there were hundreds of videos made by people who had already cast the show. People made full-blown trailers of existing footage of other actors for the roles. I had never seen anything like that. That was really unusual.

Are you doing anything specific, visually, to keep the time periods separate?

MOORE: Some of that is the on-set cinematography. We talk a lot about lighting it differently and shooting it slightly differently. And then, in post-production, we play with color timings and saturation levels, and all of those technical things, to give a separation between the two periods.

Was there a back-and-forth discussion about how many episodes to do for this season, or did you always have a set number?

MOORE: I’m not even sure where the number 16 came up, initially. I think Starz said, pretty early on, “We’d be willing to do 13, 16 or 18. Tell us where you think it is.” I think 16 was a number that was floated very early, and then I had to lay it out and see if it would be 16. It actually laid out pretty well at 16, and there was a natural break at the mid point, in terms of the story. It was up to Starz to decide if they wanted to separate them into two different sections and broadcast them that way, or not. So, 16 quickly became the number.

Do you have any lee-way with that, from season to season?

MOORE: Yeah, but we’re not quite to those discussions yet. Dealing with Starz gives you a lot of flexibility, in terms of their orders. Once we start talking about the second season, I’ll approach it the same way. We’ll break down the book, put it up on the board, and see what the natural flow is and how many episode we think it will take to tell the story.

Will you give a sense of closure to the first season, or will you also leave things open?

MOORE: The first season ends pretty much like the book does. We’re telling the story of the first book, so I’m comfortable going that way.

What’s it been like to film this in Scotland?

MOORE: It’s great. It’s been fun. We shoot on location quite a bit, so the elements are a big challenge. The hours of light are very short, so that’s a challenge. The weather can be tough. We haven’t had to break shooting or rearrange our schedule yet, which has been very fortunate, but it’s tough on the crew and it’s tough on the cast. You’re out there in the rain and sleet, and the weather changes a lot, over the course of the day. It just changes, all day long.

What have the biggest challenges been, in pulling this off?

MOORE: It’s been the logistics of it. It’s doing a show in the U.K. I did Galactica and Caprica in Vancouver, so I was familiar with doing something that’s not in Los Angeles. But there’s getting on a plane, and then there’s getting on a plane. Now, I live in perpetual jet lag. The hardest thing has been trying to commute between here and the United Kingdom. It’s very wearing, and it’s also hard to just talk to people because the time zone is so different. It’s eight hours difference, so it’s really hard to maintain contact with the writers and with post. I have two clocks in my office, in both places. That’s proven to be a big challenge. Communication between these locations is very difficult. And my wife is the costume designer, so she’s still there. Our relationship is hard because one of us is going to bed or about to wake up, and you’re trying to have moments to just talk to each other because you’re separated by this distance.

Having had your own share of fan criticism with Battlestar Galactica, did that distance you from social media, or do you want to know what the fans are saying?

MOORE: I’m always fascinated by it. I like interacting with fans and I like hearing what they say, but you have to take it all with a grain of salt. You have to realize that people who bother to log on to anything and talk about a television show is a very specific fraction of the audience. It’s not the general audience, so you can’t get too crazy listening to just that. That’s not representative, but they are the most dedicated. They’re the ones that are actually paying attention, and who are thinking about it and talking about it. Some of your most dedicated fans are the ones who hate it the most. I can’t tell you how many reviews I’ve read of Battlestar or Star Trek that would lead off by saying, “I’ve watched this episode three times, and it gets worse every single time I watch it.” That is a fan. They love the show. They just express their love through hate, which is a weird dynamic.

Outlander airs on Saturday nights on Starz.