[This story contains spoilers for season three of Daredevil on Netflix.]

Karen Page’s backstory has been a very long time coming. An unhappy home life and dark past has been hinted at throughout the run of Daredevil, but the 10th episode of season three, "Karen," finally delves deep into that history.

The episode opens on a flashback to an indeterminate past and finds a seemingly carefree and reckless young Karen (Deborah Ann Woll) selling drugs at a college party in her Vermont hometown. But the scene isn't exactly what it appears. After her mother's recent death, Karen has become the caretaker for her family, putting off college to work at her family's diner, trying to manage her father’s impulsive spending and doing whatever's necessary to make ends meet — up to and including selling drugs with her no-good boyfriend. The diner is slowly going under despite Karen's best efforts, and the mounting pressure on her soon comes to a head.

The episode culminates on a terrible night that begins with a vicious family argument and ends with Karen crashing her car while high on drugs, killing her beloved younger brother in the passenger seat. Her father, who was already emotionally distant before the accident, has never forgiven Karen, and earlier in the season can barely bring himself to speak to her when she calls. It's a brutal origin story that explains a lot about Karen's loner tendencies and reluctance to open up.

Woll spoke to The Hollywood Reporter about shooting the long-awaited backstory episode, the masks Karen wears to survive and where the character might go in the future.

The last time we saw Karen was right at the end of a very intense sequence in The Punisher. Given that, what’s her state of mind at the beginning of this season?

I tend to think of Karen as being quite lonely. Coming out of The Defenders, Matt’s [Charlie Cox] potentially dead and Foggy [Elden Henson] has this new job and girlfriend and is living his life. Then coming out of The Punisher, Frank [Jon Bernthal] basically says to me, "You can't be part of my life, and I can't be part of your life," and I have to watch him just leave and go continue to be a fugitive. So coming into Daredevil season three, it really feels like there are no connections, there's no one to turn to or to call home. I think that's why in the beginning, there's this denial about whether Matt is dead or not, when everyone else is sort of accepting it. I can't, because if he's gone, then I'm really losing every thread that keeps me tethered to this world.

What kinds of conversations did you have with showrunner Erik Oleson about Karen’s backstory?

We talked a lot, because we've had two showrunners before him, and they've both had different ideas about what that backstory would be for Karen. The main thing I wanted to express to him was that this was not a story about misplaced guilt. It's not, "I did something bad for the greater good," it’s not, "No one would blame you, Karen!" This was a story about atonement, a story about someone who made a terrible, fatal mistake and had to learn how to accept that and forgive themselves for it. Having been through what she has with her family, and being rejected after [the crash], Karen's assumption is that anyone else who knows me at that level will also reject me. So I have to hide. I can't fully share myself with anyone in my life, because then there will be no one.

Is the opening of the episode, where Karen is working this college party and selling drugs, a reference to Karen's comic-book storyline involving porn and drugs?

Yeah, I think they did a really great job of nodding to some of the themes of that story, without going fully to that trope. This felt grounded, and it felt like a story that probably many women could tell about their lives: having no way out, feeling like everything's on your shoulders, and having to make controversial decisions about how you take care of your own, while also feeling resentful of them for making you do that. That episode was so wonderful and complicated and hard, and we talked a lot about the intense slow-burn sadness of it. Even in the lighting and the way we shot it, it's very different than the world of Daredevil. It's these grays and blues, and there's kind of no color in Karen's life. She had all this promise, and it was just kind of sucked away from her, and now it's, "I have to be here, I know I have to do the right thing, but I'm not getting the help I that I deserve as a kid."

We talked a lot about the masks that we wear, and that in some ways I think Karen wears a mask as much as Daredevil does, for different reasons. There's a "party girl" mask that I have to put on in order to make that money and get the boys to buy the drugs from me, and then there's the "dutiful daughter" mask that pops up at the diner and takes care of the family. And maybe the only place she can kind of take that mask off and be herself is with the boyfriend, but then that turns so starkly on its head at the end that it makes it hard to trust, and hard to open up and remove that mask for anyone ever again.

Was the episode as exhausting to film as it looked?

It was two of the most fun weeks of my career, bar none. They gave over 40 minutes of an episode to that story, and I was so grateful for that. We took the whole crew upstate for a week, and we shot in the snow and did these incredible stunts, and they flipped a car. … It was hard, and long, and it was freezing cold, but I'm so proud of what we brought out of it, especially to highlight a complicated female story that isn't about Betty or Veronica. You can't pigeonhole Karen.

Karen strikes me as someone who deals with a lot of anxiety. Is that something you're actively playing?

Yeah, I have anxiety, and I think whether I want it to or not, that pops up in my roles. The admirable thing about Karen is that she keeps pushing through. No matter how scared she is, no matter how much she wants to let that feeling swallow her, she lets that motivate her, and I am inspired by that. I hope not to look at my anxiety, or any person's anxiety, as a weakness, so much as a motivation to say, "I'm really scared, and I don't know how to handle this situation, but that doesn’t mean that I can't." Which makes you all the more courageous.

Confronting Fisk one-on-one might be the ballsiest thing she’s ever done.

Oh my God, I love that scene so much. Vincent [D'Onofrio] and I have really been champing at the bit to get there, because we have these old resentments: He killed Ben, who was an extremely important part of my life when I first came to the city, and I killed Wesley, who was a very important part of his life. We've been at odds, but at this weird distance. What you see in that scene is that they're a very capable match, actually, and that Karen poses a significant threat to him, because she is not afraid of him the way that others are. She will put herself at risk in a lot of ways, the way that Matt will, in order to take him down.

Where does this season leave Karen emotionally?

She's confessed a lot. There's that scene in the crypt with Matt [in episode 10], and when I first read it I was like, [laughs] "OK, wait a minute. You want me to confess to … two murders? In the span of five minutes. All right!" I went home and worked on it for a solid three or four days, and I came back to them and was like, "I think I can do this, I've found a way in, if you don't mind me just shifting the order of things a little bit." In my mind, the logical process of that confession comes out of that sense of atonement. If I'm responsible for the death of my brother and the dissolution of my family, then every single step I made after that had to be about making up for it. How do I prove to the world and to myself that that's not what defines me? Flash-forward to that night in the church, and another person dies because of me. That's what brings back those memories for her.

It's also looking at Matt, and seeing him about to take this step [of killing Fisk], and caring for him so much, and I don't want his life to be like mine. I don't want him to spend the rest of his life feeling like he's a shameful person who isn't deserving of love or good things. And I don't want him to cross that line without knowing what it means. So it's offering up this truth about myself, fully expecting to be rejected. I hope, selflessly, so that he knows and can make the right decision where I made the wrong one. So that's what gave me the window into how to play "Karen confesses to two murders." It was nice also just to be back working with Charlie, because I hadn't seen him a ton during the season and didn't work with him much on Defenders or even the end of Daredevil season two. It had been a long time since I'd actually got to be in a scene with Charlie and explore that relationship.

The finale ends with Matt, Karen and Foggy reunited and about to start Nelson Murdock Page, where Karen would no longer be a journalist but still an investigator. Does that feel fitting to you?

Yeah, just tireless pursuit of the truth. I love that we see her in the stacks of the Bulletin going through old articles, and there's a line about going down to the county clerk's office and looking something up. If you're willing to do the legwork, you can find the truth! We see that so much today, there are all of these secrets and you just have to keep pushing, and it is often these journalists that are just dogged, that will not give up on a story, and will find that tiny scrap of paper that confirms something so that it's no longer a rumor. I so admire that drive, and I do think that ultimately what Karen wants to do is what Matt wants to do, which is save Hell's Kitchen. If the press was one way to do that, another way to do it would be to help them legitimately take down the bad guys. I'm excited about that future. I don't know exactly what it'll mean, but I'm glad we're all together again.