With only one episode left before “Orphan Black’s” season two finale airs on June 21, the tension is rising on BBC America’s high-concept sci-fi series, which left one clone — scientist Cosima — at death’s door at the end of last week’s installment.

Variety sat down with series creators Graeme Manson and John Fawcett at the ATX Festival to discuss the many twists of “Variable and Full of Perturbation,” including the introduction of transgender clone Tony and pro-clone Rachel’s rage at discovering that she and her “sisters” were created barren by design. We also dug into the show’s endgame and how the producers approach the show’s many challenging VFX shots, which often see star Tatiana Maslany acting opposite multiple versions of herself.

SEE ALSO: Q&A with ‘Shameless’ and ‘Orphan Black’ Stars Emmy Rossum and Tatiana Maslany

We didn’t see Helena in last week’s episode — can you give us a preview of what we can expect in episode nine now that she’s back in the clutches of the Proletheans?
Manson: Yeah, Helena is on quite a journey this year. At the core of it is this idea that we set in motion kind of early on, that she’s got this nurturing drive that she’s been unable to ever express and the fact of Kira has opened her up. We really, really found that wonderful. It’s such an important part of the twin sisterhood.
Fawcett: There is a kind of strange innocence to Helena. Amongst all her bad deeds and the craziness, there’s this kind of innocent child there. I think that’s what makes those scenes with Helena and Kira from the previous season so strong. I think now she’s in this environment where she sees her twin sister has a daughter and is around children. You can see that she really wants to be a mother, I think. It’s a strange little journey that she’s on.
Manson: She may not understand at all the science that is going on with the Proletheans, but she knows the concept. She knows what she wants, and they better watch out.

Speaking of which, episode eight revealed that the clones are barren by design, and Rachel’s apoplectic reaction to that was spectacular to watch. Why is she so fixated on motherhood? Is it similar to Helena’s drive?
Manson: It’s a little similar. I’m sure she does feel that [she’s missing something], although … it’s a surprise to us to think that [she cares so much]. But for her, it’s the betrayal of Dyad, of being the insider. You’re the elite, you’re the one who knows everything, but she didn’t know that. So, that’s a betrayal for her.
Fawcett: To some degree, too, it’s also a bit of a slap in the face for Rachel to realize that this person that she despises, that she’s at war with, has something that she doesn’t. Whatever feelings of self-worth she’s built for herself, I think seeing that really chops her down. It’s interesting I think with Rachel this season because we’ve really seen this sort of cold, hard, powerful woman. It’s nice to see the places where she’s weak or she’s human or where she shows actual emotion to us.

I love that you’ve been humanizing Rachel as the season has progressed; we don’t often see emotion from her, so her meltdown in the lab was much more evocative as a result.
Fawcett: Well, she starts life in our minds as kind of the villain. Here’s our good guy, here’s our bad guy. But that’s kind of how Helena started off too. The deeper you go with a character, the more you hang flesh on it, the more real it becomes and the less villainous she is because you start to see the living, breathing human underneath it.

Has the show’s success changed anything in terms of the way you write it? Are you cognizant of fan reactions?
Manson: I mean things like [ATX]; coming to these things; going to Comic-Con; interacting with fans is one of the most rewarding and fun things about it.
Fawcett: It’s hard to not be influenced in some ways by it, for sure. It’s fun watching them speculate on the direction that we’re going to go in.
Manson: They’re not going to convince us to #SaveCosima, necessarily. But we do put more pressure on ourselves than any network or any fan or critic could to just continually find the drive that feels fresh.
Fawcett: Also, we’re not being told what to do by networks. It really kind of comes down to that thing where you’ve got to just trust yourself. It’s great to have people that are along on the journey. But ultimately, I think you just have to go you go with your gut and you go with your instincts and just make the best story you possibly can. At some point, you really have to close people out. You’ve got to just go “what is this story dictating? What are the characters dictating?” and not let it be guided by other things. I think in a way that keeps it pure and it keeps it grounded.

Was there anything you wanted to explore in season two but didn’t have time, or had to cut out for any reason?
Manson: Yeah, there always is.
Fawcett: Things get slid around, they get moved, pushed down. You know, the Helena/Sarah road trip, we totally knew we were doing that. Camping, farting, singing along — that stuff we knew we were going to do. We came up with that in season one. It just was too soon. And Mrs. S being a badass, we knew that we wanted to see her with a weapon. [Graeme], you were like, “I’ve got to see her with a shotgun.”
Manson: We didn’t imagine she would be such a slow burn through the first season, but that’s the way it worked best.

I’m glad that you brought Art into Clone Club this season; did you always plan to tangle him up in the ongoing mystery or did you consider killing him off at any point?
Manson: [We had] no plan to kill him off in the second season. We really like Kevin Hanchard. We like him a lot. It’s important that we have those characters like Art, like Felix to a certain degree, that are outside of the Clone Club and can have our reaction to that crazy stuff that’s going on.
Fawcett: And our girls need allies too and people to help. You know, characters that aren’t Tatiana to interact with, so that not every single scene has Tatiana and Tatiana and Tatiana. I think she enjoys doing it but you have to parse it out carefully because you’re still shooting television show and we’re still on a television show schedule. That’s certainly a tricky element to designing the stories. You want to bring the girls together but you don’t want to bring them together so much that it’s unshootable.

You’ve really upped the ante in terms of the technical wizardry on display this season in the scenes with multiple clones. Has it become any easier to stage and film those scenes?
Manson: It’s not easier. We just keep pushing ourselves and the incoming directors pushed John too.
Fawcett: To some degree it’s become easier, because in season one we were trying to figure out how to do it … we tested a lot of different gear, a lot of different camera systems for doing motion control because that was a really important part of it for me — that we needed to come up with a way to allow the camera to move and to keep the camera moving so that it didn’t just have a locked off feel, which you see so much and you’re doing cheap and cheerful visual effects. We do that as well, but I’m a director, I like things to be cinematic and I like to keep the camera moving, so that was really important. So there was a big trial and error period at the beginning. Even in the first bunch of episodes … then once we knew the piece of gear that we liked, we used it a bunch of times and then we’d have successes and some failures and figured it out. It did get easier. But we are constantly trying to push the envelope and trying to figure out what is the next most challenging thing that we could try. How many clones can we stick in one scene? How much interaction can we actually get? How dynamic can we make the blocking to really incorporate the moving camera?
Manson: Tatiana had to get better at it with us technically, too. She’s really good at still managing to be natural with all of the technical calls on it. And now Jordan’s done a bunch of them as well and Jordan’s getting much better. The actors are more comfortable around the equipment.
Fawcett: But it’s a slow process. Them wrapping their head around it and getting comfortable with it is really important, because there’s nothing natural about it at all.

I loved the odd, twisted chemistry between Felix and Tony; would it be too weird for Felix to ever go further than making out with Tony, or do you intend to keep that door open?
Manson: It’s never too weird.
Fawcett: Once you’ve gone too far it’s hard not to go all the way. [Laughs.]

It’s great to see Jordan Gavaris being given more to do this season as Felix; was that a specific goal for season two — to round him out and give him more breathing room as a character?
Manson: Definitely. [We wanted to] give Jordan more to work with because he’s so good and he deserves more.
Fawcett: And we want to see that character expand even further. Felix is a big part of our story through all the rest of the seasons … wherever this thing ends, it definitely includes Felix.

The show is so dense and so layered; did you have a five-year plan figured out when you initially went in to pitch the show?
Fawcett: Oh, shit no. [Laughs.]
Manson: We had like a three season thing that we could talk through and then a cast forward demonstrating how the premise was elastic. None of that stuff held water. [Laughs.]
Fawcett: It was kind of untrue … We do have a master plan. Don’t think that we don’t, because we do! Yeah, there’s a little fluidity to it. Things port and move and we find things along the way and incorporate them and things change.

“Orphan Black” airs Saturdays at 9 p.m. on BBC America.