Time and time and time again, Marvel Studios' Agent Peggy Carter (Hayley Atwell) has proven to be a superior strategist, stronger fighter and more accomplished spy than any of her male co-workers. It should come as little surprise, then, that rather than facing off against a chauvinistic counterpart, Peggy's true challenge in the first season of "Agent Carter" appears to have arrived in the form of undercover Russian agent Dottie Underwood.

Brought to life by "Legend of the Seeker's" Bridget Regan, Dottie appears to be innocence personified on the outside, but the reality is she's trained as a master assassin. Having quietly infiltrated Peggy's life, viewers saw the facade drop when she swiftly and unceremoniously snapped smuggler Otto Mink's neck in the hallway of the Griffith Hotel where she and Peggy live. Unfortunately for Agent Carter, however, Dottie's primary target remains the future S.H.I.E.L.D. founder.

Super Smash Sisters: Analyzing the MCU's Lady Brawlers, Part 3 -- Peggy Carter

Regan spoke with CBR News about her unique audition for the undercover killer role and diving into the history of the Black Widows. We dig into Dottie's ties to the Avengers' Natasha Romanoff, her character's agenda and training, and getting physical for the role.

CBR News: Casting for superhero projects tends to be secretive, often involving fake character names or scenes. What was the audition process like for you?

Bridget Regan: The audition process was really great. One of the writers on "Agent Carter," Jose Molina, wrote two audition scenes for me. There was some talk about her childhood in the sides, so I had a feeling about who she might be. It wasn't confirmed for me in the room that she was a Black Widow until I was sitting with [Marvel Studios President] Kevin Feige going, "Oh my gosh. I can't believe this is happening." The sides were really great scenes. To be honest, I was disappointed they weren't in the show because they were so good.

Were you initially drawn to the character, or the chance to be involved in the Marvel Cinematic Universe the bigger draw?

I was absolutely drawn to both. I was drawn to everything about it. I was already a fan of Captain America and all things Marvel, but also, there was the time period and the style of the show and the themes. I liked everything about it, especially the nature of the women in this time period. Then to play a character that is answering a lot of questions about the origins of Black Widows and their training was a dream come true.

Did you immediately start to wonder if there was some connection between Dottie and Natasha Romanoff?

That was my first question. It was actually brought up because of my hair, of all things. I had red hair when I was starting on this project. We didn't want the audience to be tipped off that Dottie was a Black Widow. They also didn't want people to think every single Black Widow had red hair. We decided to make a change, but I immediately asked that question as well. The answer is, "No, there is no relation there."

Dottie comes off as the perky, sugary sweet, girl-next-door type in her first appearance. What kind of breakdown did you get for the character?

The breakdown was just something about her being from Iowa and being a dancer and coming to make it in the city, but she's not who she seems to be. Something along those lines. For me, when we had the flashback scene where we saw my younger self in training in the Red Room Academy, there was a moment where the girls were watching "Snow White" and saying words back to the screen. I based Dottie on Dorothy and Judy Garland from "Wizard of Oz." It came out in 1939, and we're in 1946. Kansas, Iowa -- I figured it was close enough. I played Dorothy when I was 16, in a musical in San Diego, so it was fun to go back and watch the movie again. I felt this innocence and curiosity worked well with this character of Dottie that the Black Widow created to infiltrate the Griffith Hotel and Peggy's life. It seemed to fit really well.

How did that little flashback to a young Dottie being trained at an assassin camp help you better understand her?

To me, it was such a gift because, often, as an actor, you have to fill in the gaps yourself. I went to set that day to watch the girls at work. I was moved by the whole experience. The set, the actress who played my teacher, all of it was a real gift. Seeing the girls being handcuffed to the bed was chilling. Once again, the art direction and everything about the production of "Agent Carter" really did ingrain in me.

So, what is your take on Dottie? Has she been brainwashed? Is she a sleeper agent, or does she embrace what she is good at?

I think Dottie is a soldier. She's trained. I wouldn't use the word brainwashed. I never thought of it like that. Yes, there's something very animal to her. She's powerful and dangerous, but she follows rules. As we saw in the flashback, with her closest friend in a headlock, when her teacher gave her the nod to go ahead and snap her neck, Dottie didn't hesitate. For me, that was a very revealing moment of her character.

There was that scene where Dottie sneaks into Peggy's room, fixates on the Steve Rogers photograph, imitates Peggy's accent and picks up her lipstick. What was going through her head? Is she obsessed with Peggy?

She goes in the room looking for the photograph she ends up taking, which is one of Stark's inventions, but she stops by the photo of Steve. In that moment, we see her fascination with Peggy. She's very curious about Peggy, and in that moment, Dottie tries her on a little bit. "What would it feel like to be Peggy? Could I be Peggy?" That moment was so much fun to play with. I think Dottie is sort of baffled by her.

Peggy and Dottie have demonstrated their physical prowess. What does a showdown between these two ladies look like?

Well, we've gotten to see a lot of Peggy's strengths already. Obviously, she's an amazing shot -- that's her skill. We've gotten to see a lot of Dottie's training. We know what Black Widows are capable of from seeing another very well-known Black Widow, who I sort of became obsessed with once I went down this road. They have very different backgrounds in terms of their training, so they would have very different styles and approaches to violence. I wouldn't say they are the same, but they would be a good match.

"Legends of the Seeker" fans know you are a warrior when it comes to fight sequences. How much fun has it been doing the choreography for "Agent Carter?"

I love any physicality that is demanded in a role. I haven't done a ton of unarmed fighting, and I wanted to brush up on that. I started working with a stunt and Tae Kwon Do martial arts expert in North Hollywood. I loved working on it. I felt like it helped me understand Dottie even more with her strength and power. It really comes from a place of confidence. I also watched a lot of Scarlet Johansson and her stunt double fight. I wanted to make sure that the fans would see a connection, even though a lot of time has passed between 1946 and present-day Avengers. I wanted there to be a connection between the two of us in terms of the dance background, the gymnastics, the fluidity and the flexibility.

What else can we expect from Dottie in the remaining episodes?

There's a lot of adventure. I feel these next four episodes are a whirlwind. The show gets better and better each episode. A lot happens. I love how quickly the truth about Dottie came out. While playing sweet, innocent Dottie is a lot of fun, playing this powerful soldier woman is even more fun.

I will say, the thing that Dottie took from Peggy's room is going to come into play.

If "Agent Carter" gets a second season, what would you like them to explore with Dottie Underwood?

I feel what we have seen of her is just the tip of the iceberg. Obviously, in that moment she is in Peggy's room, you see her try on Peggy's character. Also, we have a flashback and get to see her do a different character. This woman is capable of anything. That's startling and dangerous, but it feels like there are so many different ways the writers could go with it. That's one of the appealing things about her. Dottie is a chameleon.