WARNING: The following contains spoilers for Manifest, Season 3, Episodes 5, "Water Landing," and Episode 6, "Graveyard Spiral," which aired Thursday on NBC.

Sci-fi drama Manifest focuses on the survivors of Flight 828, a plane that mysteriously disappears while traveling from Jamaica to New Jersey and then re-appears five years later. To the passengers, no time has passed, but that's not the case for the people they left behind. Grace Stone, the wife of Ben and mother of Cal, spent years grieving their loss, and then readjusting to their presence when they returned. Throughout Manifest's three seasons, Grace has also had to deal with the suspicion surrounding her husband, son and sister-in-law, the threats they face and the strange callings that now direct their actions. Grace has served as a strong anchor for her family through everything, yet it wasn't until Season 3 that she reached out to someone from her past for help. The introduction of Grace's stepbrother Tarik (Warner Miller) has filled in Grace's backstory while giving Karkanis the opportunity to reveal new sides of her character, especially in the most recent episodes that aired on Thursday.

In an exclusive interview, Karkanis spoke to CBR about Grace's arc in the first half of Manifest's third season, the thrill of playing a badass and what's coming up in the second half of the season.

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CBR: Grace has been fighting for her family in one way or another for almost three seasons now. What's it like to play a character who's almost always trying to protect someone she loves?

Athena Karkanis: Yeah, it does feel like she's getting to be a bit battle-worn. I think this is a show where it constantly has to be the stakes getting higher and higher and sort of more and more peril and strife for the heroes of the show. So, I mean it's exciting. We don't live our lives that [way] -- well maybe this year we have -- but we don't live our lives in constant fear in real life, and so it's kind of exciting to get to explore that in a character. I think it's interesting how we see this other side of Grace in the sixth episode [of the third season] and we see her again fighting for her family but in a very different way than we've seen before.

This season, for the first time, we meet someone from Grace's side of the family. Have you enjoyed being able to explore this new side of her?

Yes, very much. In fact, it was actually an idea that I had pitched to [showrunner] Jeff Rake that I kind of thought it was funny that we had never met anyone from Grace's side of the family, given someone who has gone through everything that she's gone through -- half her family disappears and then they come back and then she has a baby -- and there's nobody who ever shows up at the doorstep being like, "I baked you a casserole. Do you need anything?" So I was really excited when he told me that he was going to add this estranged stepbrother character.

And I really enjoyed that arc because Warner Miller, who played the role of Tarik, is wonderful; we got on very well and he's talented and great to work with. It was fun to explore a different side of Grace -- who Grace was before she was Ben's wife and Cal, Olive and Eden's mother. And I think it's fun for the fans too, because there are some fans who really love Grace and I think that will be exciting to see her just wearing a bit of a different outfit.

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You and Warner Miller have created a really believable bond between your characters. How did you go about developing this sibling relationship together?

Well, we both have our own sibling, so we have that experience. But also, I think we just got really lucky. We really clicked right away. And he's good. It's always easier to do good work opposite a good actor. So it was a bit of luck, it was a bit of life experience and it was a bit of just, "Well, I'll do my best here."

You shot the show during COVID. Did that change the way you could work together, both with the actors you've been with for years and also with Warner who was coming in new?

Yes, it did, definitely. The protocols that we were working with were very, very strict -- like extremely strict. Anything that SAG [the Screen Actors Guild], our union, had laid out, we did and then some. We were getting tested daily […]. Everyone was masked at all times except for if you were in front of the camera. […] And as much social distancing as possible. It makes it hard to do your work that way but it also kept us safe. And I did feel safe. I was pretty worried about going back to work when COVID hit, but I felt really safe on set. From my first day I was like, "Oh, okay, I feel okay here."

And in fact, that was proven because we did have some positive cases in the crew, and any of those cases, nobody lost their life and nobody was seriously sick, so that's something we're all very thankful for. But also those people didn't transmit it to anyone. So as soon as somebody tested positive, they would identify their contacts and those people would also have to isolate for two weeks and get tested, and in all of those cases, none of those close contacts ever tested positive, so it really was a testament to the protocols we were taking and to the efficacy of the mask, because everyone was masked at all times, and it just really kept the transmission at zero. The people who got it, they got it elsewhere.

We all just feel so lucky, because it was kind of a risky thing to be doing in the grand scheme of things, where like most people are just staying inside their homes […]. And crews are big and it's a lot of people to expose yourself to, but because everything was so strict and it was so by the book, we managed to get out unscathed.

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In the episode "Graveyard Spiral," for the first time since Flight 828 disappeared, Grace experiences a real loss, not just the threat of a loss. What was the experience of playing that for you?

That was great, actually. That day I felt like the scene went really well. It's not always easy to get to that emotional place in a truthful way, and especially with all the pressures of like, "Okay, we gotta go now." But that day I just felt like I had access to my emotions and I was happy with how the scene went. And I was very sorry to see Warner go because he was a lot of fun to work with, although that wasn't actually the last day that we worked together because we shoot out of order. And I think it's also great for Grace to have this other thing in her story that's not 828.

I loved that Grace also becomes a gun-wielding badass in the episode.

Yeah, that was a lot of fun too! [Laughs.]

Did you enjoy being able to take her in a direction we haven't seen before?

Oh, absolutely! I was thrilled! That was a lot of fun for so many reasons. First of all, it's just fun to play a badass. And secondly, because I knew that the fans would be losing their minds, because it's, as you said, not anything even remotely close to what we've seen from Grace so far. Literally, I have lost count of how many times I'm baking cookies in the show over the past three seasons. So, it's a real surprise. And I think that's great -- and then it's also like a pleasant surprise because everybody loves a badass.

So it was a lot of fun. I had rifle training so that they showed me how to hold a rifle like a real hunter would so it would look really cool. And I made sure that the gun guy took my picture so I could send it to my dad, who is a hunter, and I thought he would be impressed seeing me holding a hunting rifle the right way.

And I also just loved being able to play that strength that just comes from this deep well. I read a story a while ago about an Inuit mother whose child was being mauled by a bear, and she attacked the bear -- like a polar bear or something. And she attacks the bear and fought the bear off of her child. And it's this amazing strength that a mother, [her] inner cave woman can just come out from this deep, deep place. You can be a cookie-baking suburban mom, but deep down inside, there is a polar bear fighter. [Laughs.]

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Will we get to see more of this side of Grace in future episodes?

Unfortunately, not really. The polar bear fighter goes back to her corner of the boxing ring. Yeah, I also was like, "Jeff" -- our showrunner -- "is there going to be more of badass Grace?" But I think she has to kind of step back into place because the story goes crazy […]. I like to describe her as the peg that keeps your tent from blowing away in the wind. She's sort of the stable one; the foundation of this family. There's always so much crazy stuff happening for Ben and Michaela and stuff like that, and she's holding down the fort.

In the episode, we also learn completely new information about what the survivors have to do to live past their death date. What will that mean for this story moving forward?

That's a really huge reveal as far as the direction that the show is going to take and the things that Ben and Michaela start to pursue as far as surviving the death date. Also, not to get too philosophical, but I also feel like it's such an allegory for where we are in the world today with COVID. […] In the early times when it was like, "Oh, we have to protect each other by staying at home and staying away." And then once everyone started mask wearing it was like, "We protect each other by wearing our masks."

And now we're in the phase where developed countries are getting vaccinated and other countries are not getting vaccines, but then the virus is mutating and that's just going to make its way back into the rich countries that are vaccinated, protected against these new variants. And so it just kind of feels like, "Oh my God, we're in such a lifeboat." This whole thing has been such a lifeboat in different ways along these phases of the COVID-19 pandemic. I don't know if that's too philosophical but I couldn't help noticing that parallel.

And maybe it's kind of how humanity should always be thinking. What's good for everyone is always what's good for everyone. Unfortunately, we're not usually like that -- we're mostly out for number one. But maybe it's not a bad lesson.

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Can you tease what's next for Grace?

Well, there's a lot more. I'll tease this: the [third season] finale is insane. Killer, amazing, mind-blowing. That's all I can say. The next half of the season, there's a lot of excitement and twists and turns and turbulence -- pardon the pun -- as there always is in this show. But the finale -- hoo! -- it's a showstopper. But hopefully it won't be a showstopper -- hopefully we'll get another season. But the finale is really good.

Manifest stars Melissa Roxburgh, Josh Dallas, Athena Karkanis, J.R. Ramirez, Luna Blaise, Jack Messina and Parveen Kaur. It airs Thursdays at 8 p.m. ET/PT on NBC.

NEXT: Manifest: Will Peltz Talks Joining the NBC Series as Levi, Teaming Up With Olive