Syfy debuts its brand new series Defiance tonight, April 15, with the Pilot episode airing at 9 PM ET. The show is set in a future St. Louis, where several alien races have arrived and transformed the planet, with both species trying to find a way to co-exist peacefully. Series stars Grant Bowler (Jeb Nolan) and Stephanie Leonidas (Irisa) recently held a conference call where they discussed their roles on this innovative show set in a world that fans can also explore through a video game which takes place in San Francisco. Grant Bowler first spoke about acting in an environment with a lot of green screen, where he had to pretend certain things and people are there when they really aren't.

"They're exhaustive in they provide a storyboard. They generally do rough renders of the scene for us with 3D animation so that we have some idea what these things are going to look like, what the vista is going to be. And then it's a process of all of us getting together and going okay well there's a tall tower, where's that and someone sticks a tennis ball where the tall tower is, and where's the nuclear, I don't know, main nuclear power plant and where's the park and where's the horrid alien and how tall is the horrid alien and how fast it coming towards us. And then once we map all of that out then it's kind of like being a kid again, you're just playing make believe. I find it kind of gorgeous as long as we're all looking in the same direction. When you're not looking in the same direction it gets very awkward very fast."

Stephanie Leonidas also added that the days in front of the green screen were often the longest days on set.

"I mean the green screen were always the longest days to shoot. They were kind of the days you had to really kind of be with it before. But like Grant said we had the storyboard were incredible so it wasn't like we didn't have any idea what they were going to do with it afterwards. And I guess I was kind of lucky I've done some green screen before Defiance which really helped so I didn't feel like I'd been thrown completely into the deep end with it. But yes I feel yes we're really lucky with all the storyboards and kind of everyone around that. It's just yes given us a great idea of what it's all going to look like in the end. I mean I guess they could do anything. They could put the Muppets in there for all we know but yes it was - they were long days but I think they'll be worth it in the end definitely."

Stephanie Leonidas also revealed that it was the human drama in this unique world that ultimately attracted her to this project.

"I think the thing that first attracted me to the script was the fact that it wasn't kind of just this apocalypse story with aliens kind of fighting each other. It was kind of a real human drama to the piece and it felt like there was real heart to it and the characters had stuff that people could relate to I guess even though they were these aliens with prosthetics on their head. So I think that's what really attracted me to it that there was real drama to it and those are always kind of my favorite scenes to play like those scenes with Grant in the car and stuff with Tommy and the other Irathients. There was some really nice stuff there so that's what yes initially got me really into the script."

Grant Bowler added that he is not necessarily interested in the sci-fi genre, but that he was drawn in because of the world that was created.

"For me it was all the way from its inception. The first thing that attracted me was it's funny because like I'm kind of very well known let's just say amongst my representatives to not be terribly interested in receiving sci-fi scripts and the first time that the script went across my agent's desk she didn't send it to me because she thought I'd get angry at her. But the casting agents asked me about a month later. They said why didn't you respond to that script? We sent it to you deliberately because we thought you'd love it and I kind of double checked on it. Defiance is different than anything I've ever read and I guess that's the key. Ultimately as an actor and as a storyteller you're looking for a story that hasn't been told and 99 out of 100 pilots that you receive you've seen it before, 99 novels, 99 movies out of 100 you're read or you've seen before and Defiance was a world that I hadn't seen before. It was a genre that I hadn't exactly seen before. And the dynamics in terms of the characters, this kind of grizzled kind of scavenger and an alien adopted stepdaughter, all of these - the setup of the Capulets and the Montagues with the Tarrs and the McCawleys, with a Lady Macbeth-ness of Datak's missus, you know, the Romeo and Juliet story. They're fantastic dynamics that were set up right at the beginning and that was what kind of grabbed me was a world I hadn't seen before, a story I hadn't seen before and these incredibly kind of strong, epic Shakespearean dynamics."

When asked about the challenges in taking on this role, Stephanie Leonidas revealed that applying all the prosthetics was the first obstacle to overcome.

"Well, well challenges I guess I have a lot of plastic on my face. Yes I am half in prosthetics to that was kind of the first challenge for me I guess. I've never had a prosthetic like that at all so yes that was the first hurdle I guess. In shooting the first episode I think it was we were thrown completely into the deep end. I mean it was the - the first scene of the day was this scene where Nolan and I are arguing and it's quite an emotional scene and the weather was against it. It was freezing cold, it started to snow, it felt like a big mess actually. So yes it was kind of - I remember just looking at Kevin Murphy going oh my God, oh my God. We were really thrown into the deep end. But I'm kind of thankful of that really because yes it made everything feel a little easier as we went along. So yes we were in the middle of quarry, it was kind of out in Oxbridge in Toronto so yes it was yes quite an epic first day. But yes a good challenge."

Grant Bowler also spoke about the exacting standards they have for the wardrobe, and discussed playing an anti-hero.

"The fact that they were so exacting on our wardrobe and the wardrobe design is just stunning on Defiance, but the results of all of these arguments and conversations in creating this wardrobe meant that our gear and my jacket and I'm certain Stephanie's stuff were like finished being made in Toronto at about 5 o'clock a.m. the morning we were shooting. We were on a 5 a.m. call so we were through makeup, dress and rehearsing before the wardrobe arrived. And as a result of that nobody thought about the sudden shift in the weather overnight. So there's a whole sequence of stuff where Steph and I are meant to be cold and miserable in the Badlands, especially the stuff where we're running from the spirit riders and have a little confrontation with the crazy alien timber wolves and there was no acting in any of those scenes. We didn't actually - it was we were soaking wet and it was snowing so we were freezing to death. And that was kind of good. Steph talks about the madness of it and that's absolutely right. But it's going to be mad. You're jumping into a new world all of a sudden and its' going to be nuts. In terms of acting challenges for me it's really - you're playing a role that is an archetype. The antihero is an archetype now and there's been so many great ones. So for me the whole challenge is if you look updating and rebooting an archetype and trying to figure out, A, what new can be done, how can I tell this story of this archetype in a different way that I haven't seen before that I'd love to watch. And also the other aspect of updating is what's changed, you know, like you look at say an archetype of Dirty Harry. Now that character then everything Harry does is incredibly shocking and there were whole articles and theses written about Harry Callahan in psychology. But if you look at Harry Callahan today and measure him against Denzel Washington's character in Man on Fire, Callahan's tame because society's changed, social mores have changed. So every time we reinvent a story, every time we reinvent an archetype, it's interesting to look at okay what's different, how do I update this archetype, this character to move into 2013 and hopefully hold for as long as possible so that it stays relevant and doesn't date. That would be mine."

Defiance debuts tonight, April 15 at 9 PM ET with the Pilot episode.