Meet Mia Smoak! 'Arrow' Star Katherine McNamara Dishes on Playing Oliver and Felicity's Daughter (Exclusive)

Katherine McNamara Arrow
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'Arrow' just revealed the true identity of Katherine McNamara's character and we're having a full-on family freakout!

Holy Smoaks! Arrow just revealed the true identity of Katherine McNamara's character and we're having a full-on family freakout!

Monday's new episode of Arrow, “Star City Slayer,” dropped a bombshell in the show's future timeline to reveal that the bad*ss cage fighter Blackstar is actually Mia Smoak – the daughter of Felicity Smoak and Oliver Queen. (We totally called it, by the way.)

Naturally, we hopped on the phone immediately to discuss the revelation with McNamara herself, who was just as excited as we are! “Oh my god I’ve been dying to talk to someone about this,” she gushed to ET. “I‘m so glad that the cat is finally out of the bag!”

Read on for exclusive behind-the-scenes secrets about Mia Smoak’s script-to-screen reveal, whether or not Olicity fans should be worried about the fate of their favorite couple and if McNamara is ready to take on the salmon ladder!

ET: Take us back to the beginning, Kat. How did this role on Arrow first come to you and did you know all along that you were going to play Oliver and Felicity’s daughter?

Katherine McNamara: So I knew before I started shooting. But when I initially auditioned, they, of course, did not reveal it to the people who were going up for casting. They [gave me] dummy sides and I believe it was a couple of scenes of a rookie cop or something, so I knew basically nothing. Then after I was cast, I get a phone call from Beth Schwartz, the showrunner, and she said, “Oh yeah, congrats on joining the show! By the way, everything you know is a lie. You’re Oliver and Felicity’s kid – so congrats and have fun! Thanks, I’ll talk to you soon.” And I was like, “Wait, wait, wait! Hold on! Let’s press rewind - excuse me?”

Immediately, my first thought was what a responsibility this is. I’ve seen the power of not only the Arrow fandom, but how much they love Olicity. How much this relationship is beloved by them and how passionate they are and how many opinions they have about it – so I know how important this is going to be for the fans if this is done right. Then I proceeded to watch all six seasons of the show and do as much research on the comic wikis and the show wikis and everything that I possibly could. Beth had said to me that they wanted her to be the perfect blend of the two of them – to be physically everything Oliver Queen and then intellectually everything Felicity Smoak, so I had my work cut out for me.

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During your Arrow research, which Oliver and Felicity mannerisms did you choose to infuse into Mia?

Well, with Oliver’s physicality, obviously, I’m never going to look like Stephen Amell! [Laughs] No matter how much I work out or how much grilled chicken I eat -- that man is on a whole different level. But what’s neat about bringing that into a character -- especially a female character -- is to find really interesting ways to bring those kinds of masculine physicalities and the very offensive and aggressive way of moving into this character. It adds a very interesting quality that we haven’t necessarily seen in many of the characters in the Arrow'verse yet. She is very much like him in many ways, but also, you have these qualities of Felicity in her: her wit and her tact and her intellect and the way in which she thinks about things and plans and strategizes. Something you’ll find about Mia that you’ll love, as time goes on, is she has quite the mouth on her. She’s quite snarky. We’ve seen a little bit, but it only grows and I think that comes from combining Felicity’s humor and wit with Oliver’s aggression and brutishness.

What are the chances we’re going to see you tackle the salmon ladder?

I have not done so as of yet, but I can only imagine that it’s going to be one of these days. That was my first question to Beth, by the way. “When do I have to do the salmon ladder? Because I have to start training, like, yesterday!” [Laughs] You know me well enough to know that I’m constantly training anyway, but that’s a new level of intensity.

In this episode, we discover that her name is actually Mia Smoak instead of Mia Queen. Can you elaborate on that a little bit and when we might be getting those surname answers?

I can elaborate in the sense that you will be getting those answers -- but maybe not as soon as you’d like. In a few episodes, there will be an all-future episode where we really get to see a lot of Mia’s childhood and a lot of moments that really shaped her into who she became and why those qualities are the way they are, including her last name. But for now, it’s enough to know that she is Mia Smoak and she claims to be the daughter of Oliver and Felicity. So she knows that Oliver is her father, but does not take his name. Ultimately, the most important thing to know at this point is that this is indicative of how dire the world has become... To know that even having the last name Queen puts a target on your back.

You know that the Olicity fans are the best detectives of any fandom. They’re probably going to be worried when they hear that her name is Mia Smoak instead of Mia Queen and wondering what that means for Olicity’s relationship in the future. Should the fans be worried?

Maybe. I actually don't know the answer to that question yet because we’re still shooting season seven right now, so I don’t even have all the answers... but, maybe. Even for me, that’s still a question mark.

Were you surprised when you realized that Mia Smoak and William Queen – who are half siblings –  don’t know each other in the future?

I was surprised and that was another question I had for Beth. Thank god for Beth Schwartz because she has been such a lovely, collaborative wealth of information for me. There are many things that I don’t have the privilege of knowing yet, but she’s been so good to me in that I can call and ask her a question and she will give me some kind of answer to do my work off of that does not reveal what they still want to keep hidden. So thank goodness for her. But aside from my tangent, that is a very interesting question and one that we will get the answer to very soon. It all goes back to the ruin that Star City has fallen into and showing the real lengths that Oliver and Felicity had to go to to keep their children safe.

What was your first interaction with Stephen Amell and Emily Bett Rickards like?

Well, it’s very interesting. I met Emily a few years ago just in passing because she and [Shadowhunters star] Isaiah Mustafa are friends, so I had already adored her because she was just so kind to me and just such a fun human being. And then re-meeting her was, of course, lovely on set because she’s just an amazing, kick*ss human being. I’ve really loved getting to know her and kind of pulling whatever qualities I can from her and from Felicity, and putting them into Mia because it can be a challenge to find those sorts of lighter and interesting qualities. Emily has just got this inner strength that I love at her core and that’s something that I’ve fed off of a lot with Mia.

Stephen, actually, was the one that I re-met first when I was coming onto the show. I was there for a meeting of some sort and Stephen was shooting the “Slabside Redemption” episode, so he was, of course, covered in blood and scars and [had] a million other things on his mind and [was] obviously exhausted. But he happened to pop his head into the hair and makeup trailer and he stopped everything that he was doing, jumped out of his chair, came over, gave me a hug and had a long conversation with me and really, really made me feel welcome. To me, that’s such a testament to his character as a human being, and just who he is as a person and why the show has such a positive environment on set.

It’s been really fun seeing these flash forwards bringing a new chapter to the Arrow 'verse. What does it mean to you to be a part of the next generation of vigilantes? 

It goes back to the responsibility that I realize I have with this character and whatever it ends up being. Just even being a part of the future and being a part of this universe is really wonderful. I mean there are so many interesting facets to the Arrow 'verse with the future with Nora that we have now on The Flash, and with Legends everywhere and now with having Ruby Rose as Batwoman and all of these incredible characters. There’s just so much diversity and inclusivity and all of these things that are happening in the Arrow 'verse. I’m so thankful to be coming from Shadowhunters which had a very similar environment, vibe and mindset. It’s really wonderful to still be part of that and I understand the responsibility and I’m excited for the challenge ahead.

Oh my god. We need you and Nora to be together and hang out!

[Laughs] l’m down! You set a time and we’ll be there.

We know that Mia is not necessarily a fan of vigilantes but how ready is Kat to suit up?

Oh I’m so excited! I mean that was always one of my favorite elements of Shadowhunters was when Clary really got to buckle down and kick ass, and yet we really didn’t get to see that as often as we would’ve liked because Clary was so new to the world and she was still learning so much. But now we have Mia who, we’ll see very soon, is well versed in fighting and suiting up in her own way. Getting to see this character who very often finds herself in these situations, it’s a real treat. I remember watching this show as I was gearing up to start shooting Arrow and figuring out who Mia was and what this would entail. It’s so exciting. As an actor, there's certain moments where you’re on set -- whether you’re in the woods with Seelies and vampires and running around the forest with swords, or you walk into the Arrow cave, even if it’s covered with vines and waterfalls -- just knowing who you are in that universe and what a thrill it is is. There are moments that are really special and you just want to pinch yourself a little bit and wonder if you’re dreaming or if this is actually what you do for a living. It just really makes me eternally grateful to be part of such a cool and interesting project.

So where do we go from here? You mentioned that we are going to have an all future episode. Now that the team knows who she is, how does this change things moving forward?

Well, it definitely changes things and it definitely provides a lot more information to everyone and fills in a lot of the missing pieces for both parties. Mia doesn't know everything about her past, William obviously doesn't know everything and neither do the characters of the future, so as all of the pieces come together and as everyone combines their knowledge or at least reveals certain pieces of information -- for better or for worse things will move forward and things will progress very quickly. As you will see, time becomes of the essence and don’t forget, they did find those bomb schematics very recently, as well, so the future [could have] explosive content if you will.

Arrow airs Mondays at 8 p.m. ET/PT on The CW.