The Winchesters star Bianca Kajlich talks ditching Millie's coveralls to join a hunt

Millie Winchester (Bianca Kajlich) is getting in on the hunt.

In this week's episode of The Winchesters, John's (Drake Rodger) mom is leaving her coveralls behind as she teams up with Mary (Meg Donnelly) and company to help save her son from a monster. EW spoke with Kajlich about Millie's growing involvement and her experience joining the Supernatural universe.

ENTERTAINMENT WEEKLY: I feel like I should start by congratulating you on getting to wear a onesie in so many of your scenes.

BIANCA KAJLICH: It is my favorite costume that I've worn to date. In fact, I actually have a little visceral disappointment when I step onto set and I realize it's a day I'm not in my coveralls. [Laughs] They're pretty cool in the summer months, and they're really warm in the winter.

My first thought when Millie wore high-waisted jeans in this episode was, "She's not as comfortable."

No, I'm not. I really am not. But I am feeling very happy that I am doing a show where I get to wear such flattering clothing because it really is. Everybody looks good in that stuff.

Totally. Well, before we dig into this episode, I want to start with just, before you even got this role, what was your knowledge of Supernatural? Were you familiar with this universe?

My knowledge of Supernatural is that I worked with Jensen [Ackles] on Dawson's Creek back in the early 2000s. I knew that he had gone off and done this show, and that it was very successful. But I had literally never watched an episode. And funny enough, I have dear friends that I did not realize did not miss an episode. So, when I booked this, they were dying. I'm like, "Are you serious?" My one friend that would be the last person on this planet that I would ever think would watch something like Supernatural, she was like, "I never miss an episode." It was my first clue that I was stepping into a world that was beyond anything I had ever experienced.

How was Millie initially described to you?

Well, I didn't really get a description. I literally got the pilot script and I got the breakdown of the character. The way that she was initially written is not that far from what you see in the pilot, but she was definitely a little more country. But she was very full-bodied. There's auditions that I get where I definitely feel like I have to reach a little bit for what I'm doing. This one, I felt like she came in full force. I think just the mechanic of it all and her having her own garage, that was a very loud statement that was hard to ignore. So, I was super excited because what a badass character.

And this week, she gets to be even more badass and get in on the hunting a bit!

I remember talking to [showrunner] Robbie [Thompson], and at one point he was like, "Yeah, Millie will eventually come into the group more and she will go out on the road as well." I was like, "Oh, really?" I hadn't even just pondered or dreamt about that. To me, it was so rad that she was just this woman in her garage. It never even occurred to me that maybe she might go out into the world. These are the roles that you see other people playing and you're like, "Why didn't I get to go out for that?" I couldn't believe it was mine. I feel so special and so privileged to get to play her.

It's also feels like such a nice addition to have her very adult energy in the mix.

Yeah, especially because the world is so precious to them. Mary comes from a family of hunters and John feels like this was literally the calling of his life. He was born to do this. So, for them, it's all very precious. Whereas for Millie, I think it's just like, "What do I need to do to get from point A to C? I don't care about all the particulars, just, what do we need to do?" I do think every group needs a leader like that. We would all be a lot more efficient if we had someone like that.

The Winchesters airs Tuesdays at 8 p.m. ET/PT on The CW.

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