[This interview contains spoilers for the Sept. 24 episode of Better Call Saul, "Coushatta."]

Rhea Seehorn's Kim Wexler, both solo and in her relationship with Bob Odenkirk's Jimmy, has always been the heart and sympathetic soul of Better Call Saul. But what has often been just beneath the surface has become the centerpiece of the current fourth season.

Don't believe me? Ask Oscar-winning director Guillermo del Toro, who caught up on Better Call Saul last week and eagerly tweeted, "Kim is the key!"

He's correct, of course.

In recent episodes, excitement and also heartbreak have come from watching Kim take her most active role yet in Jimmy's descent into grift and cons, helping orchestrate the elaborate scheme to liberate Jimmy's bodyguard Huell (Lavell Crawford). It was a perfectly executed trick that got Kim a little hot-and-heavy, reminding us of the second season episode "Switch" and Kim's previously established attraction to Jimmy's dark side.

It felt like a big fall for Kim after her recent public defender work, which she'd taken on as almost atonement for her commitment to helping Mesa Verde cut various banking corners.

Or was it?

Seehorn chatted with The Hollywood Reporter about the conflicted desires driving Kim this season, Jimmy and Kim's rare moment of on-screen physical intimacy and the benefits and frustrations of spending most of this season acting with an all-too-real cast on her arm.

I want to start by asking the most pressing question about last week's episode: How hard is it to remain serious and romantically invested in a scene with Bob Odenkirk doing his Cajun chef accent?

Well, luckily, they had Kim laughing. When he actually does the impressions for me, when we're laying in bed, it was a great and fortunate thing that Kim is actually supposed to be laughing, or else it would have been a lot harder for me.

We've known since season two that Kim has this side of her that kinda gets off on these con games. How do you think she looked at that side of herself in season two, and how does she look at that side of herself now?

That's an interesting question. There's the evolution of that particular strain in her that we don't really know yet if it's innate versus acquired; and if it's acquired, then, where did it come from? Of course, I do think from the beginning there's been a, not only attraction and repulsion she has with doing cons and pulling off little scams, but a strange … What's the right way to put it? The first time we saw her do it with Ken Wins, there was a repulsion at first, but then not only was there an attraction, but there was a seamless skill set that appeared, that she was good at it as well.

I feel like her embracing that and then in this latest one, initiating? Yes, Saul/Jimmy asked for her help with Huell, but the entire con, she made up. Now, Jimmy added the phone, as he says in that one scene, and obviously pulled off these incredible performances and orchestrated it, but she planned it, and he gives her credit for all of that. That, to me, was an evolution for her to go from being a passive participant who may or may not have familiarity with that sort of stuff to someone who's actually planning, conceiving and then as we saw at the end of the episode, actually initiating a scam. That's certainly an evolution that I thought about and really had fun playing with. How much can she enjoy it? How much does she check in with herself?

But we'd seen her this whole season — there's a lot of very impulsive behavior coming from her that we haven't seen before, and you can tell that it shakes her, whether it's hanging up on Paige at Mesa Verde or blurting out inappropriate comments about Kevin's statue. Even in this last episode, "Coushatta," there was that subtle part where, yes, she's sort of bored at this office meeting with Mesa Verde after she's done this con the day before and had a great evening with Jimmy, but it's not just that. You see her subtly surprised that she was even able to say "no" for the first time to a client. When he's like, "What if we took over 600 other places and put statues in everywhere?" She's like, "No, we can't do that. It's too late. We've already turned in the permit bonds and this, that and the other." They have all these other things weighing in, too, that Kim's sort of wrestling with conscious versus unconscious behavior and is mildly uncomfortable with being impulsive, but can't stop herself.

Do you think that she's convinced herself at this point that there can be an altruistic side of this? That she's fighting the system to some degree, and that allows her to rationalize what she does with Huell here?

I definitely think so. I look at that a lot. The writers are really deft at that. Even when deciding to help Huell, in that scene from the week before last's episode, by Alison Tatlock and Deborah Chow, you see Jimmy come in, ask me to help him with Huell, but he unloads all this behavior on me of, "I'm selling cellphones in the parking lot and I have a friend who may or may not be a known pickpocket that's such a close friend that I need to bail him out." There's all this information and "Can you help me get him out of trouble?" But what the writers do again and again that I just love is there's always another side. Whether it's Ken Wins being scum, and he's actually trying to get one over on us, and Kim decides that, "Oh, this guy, quote unquote, deserves it."

With the Huell case, not only is it Jimmy asking me for help and I do care about him, but they added in this element that he feeds me that there's been an injustice. There's been a horrible injustice here where this man is falsely accused, and the more Kim digs, the more she finds out that he actually is being punished to a much greater extent than any of the other ADA's clients. She does hang her hat on that, and I do think she keeps drawing some very dangerous lines in the sand for herself.

We've all been there. If it's a small misdeed that really doesn't actually hurt anybody? Okay. In the case of Huell, she says, "I'm not going to tear a cop down," which was Jimmy's plan to get Huell off. Instead she decides, "What if we build Huell up? What if we make a hero out of a man — completely illegally and falsely — but we didn't actually say anything negative about the policeman, so that's okay, right?" It's a very dangerous line to be making, in my opinion.

When she started loitering in the courtroom and then doing the public defender stuff, the pro bono work, what do you think was the driving force of that instinct?

It is a different type of thrill-seeking for Kim. The cons and impulsiveness in other areas that we're seeing now, to me, were always there. They just come out in different forms, but she has an element to her that, like Jimmy, has a problem with settling down and just going toward stability and making a lot of money. She has a different sense of what's a thrill ride for her than Jimmy does sometimes, but they both have that itch they need to scratch. She thought that the law was going to be — even though she, as we saw in the flashback, is pretty nerdy about what's exciting to her, like case law — about fighting the great fight and everything that the judge makes fun of her, that Ethan Phillips played so well, in that one episode where he was like, "I've seen a million of you guys trolling around, looking for PD work that makes you feel whole again," and he's right. He's mocking her, but he's right. She didn't want to just help the world have more mid-sized banks. That wasn't the plan, no matter what that paycheck offers.

There are times in her life where even looking for the big clients was often about, "How can I pay my bills in a stable fashion so that I don't owe people money? So that I'm not under somebody's thumb? So that I can make independent decisions for my life?" It was never about being the queen of banking law and making a gazillion dollars. I think the adventures and the PD work, to get back to your question, is still about having control over your own life and feeling like she is a crusader of sorts. It's another version of righting the wrongs in the world, in her mind. That's what that was about. Like, "Is there a way that I can pay all the bills? Make sure that I can take care of that because I'm really not sure how much Jimmy's cellphone job pays, and when he'll be able to practice again and we're working out of my house, this, that and the other. But is there a way to do that and still feel like I'm doing something in the world?"

I think in a season that's so plagued by different ways in which we grieve and deal with guilt, with the Chuck thing looming over us, it became even more imperative for someone like Kim to feel active, because she doesn't seem to be able to save Jimmy. Whether it's asking if he is interested in a therapist or he wants to talk or do you want to get drunk or do you want to have sex or do you want to not talk, and we both just work? There's an instinct there to fix things. She's absolutely a fixer, and I like that about her. It's a more stereotypical male behavior that you see on TV sometimes, like, "No, we don't need to chat about our emotions, let's just problem-solve." I think it was all part of that pull that Kim needs to fix things and it's a bit obsessive when it's out of control.

Now, this episode highlights the physical affection between Kim and Jimmy, and that's something that we haven't actually seen that much, really. Have you and Bob or you and the writers talked about when they want to show that side of the Jim and Kim relationship, rather than when they just prefer showing them as almost the old married couple, which I feel like we've seen a lot this season?

They aren't, like, "Two times this season we're going to show some affection, so everybody batten down the hatches." They don't do that, but yes, I'm aware that they don't show it a lot. This season has a lot of other stuff going on as far as them drifting apart and having difficulty speaking to each other. It's quite tragic, and so that part of that ennui that they were showing this year is very purposeful and quite sad, that these two people are beginning to lead secret lives themselves and seem to be quite fearful of letting the other person in on how much distress they're in in their minds — both of them, for different reasons — and that, to my mind, is what starts to isolate them and put them in bubbles, and it's just so sad. If they could have actually laid bare everything to each other for much of this season, they might have been able to help each other. I think those isolated pictures of a couple, they're tragic and they're pretty accessible to the people I know. We've all been through those periods. It's just that these two people have extreme circumstances.

Other than that, the affection stuff, it's funny. I know people noticed first, like, "Oh, there seems to be a lack of sex scenes" or "They don't have the giant kisses now and then or all the time." And I also hear almost the opposite as well, of people saying — certainly not this season, like I said, this is a different season — but in other seasons, I would hear people say to me that they think they look like a real couple. Jimmy and Kim seem like they actually really do love each other and it would come in the form of not having scene after scene where you wake up naked in bed, and make sure you show us with rumpled sheets, but instead it was asking somebody what they want them to pick them up for dinner or when they come home and putting your feet on somebody's lap when you watch movies or always answering somebody's phone calls, no matter what you're in the middle of, or being able to have an argument and not resolve it at the end because you know they'll still be there in the morning. That really hit a lot of people as actual love, more than a sex scene, and I've enjoyed that reaction to them.

I think you're right and I think it's utterly authentic, but is it always clear to you guys when a scene that is, for example, just them saying, "What do we want to get for takeout tonight?" when that's a sign of affection and all of the things that can go unspoken in a relationship versus when it's a sign of estrangement or chilliness? Because it's the kind of thing where the exact same line could be one or it could be the other, depending on how you guys take it.

It is clear. Sometimes it's a tone note in the script, and other times it's a discussion with Bob and I and the writer and director, and/or Peter Gould. Other times, it's something Bob and I just feel and play, but we do play scenes a lot of different ways. Often, there's multiple takes that have performance range in them — not so much as, technically, "Something went wrong." It's more exploring because they are very subtle scenes that do not always have an obvious arc or an obvious one main intention. They're winding narratives.

For me one of the sweetest, most loving scenes that Bob and I enjoyed playing so much because it was so small and so quiet, Michael Morris directed it and Ann Cherkis wrote it, and we're sitting on the bathtub and he actually was attacked selling cellphones in the parking lot, but he tells me he was mugged. It's the middle of the night and I wake up and I'm putting on bacitracin and, for a second, he almost tells me that something really is wrong, and he says, "I think there's something wrong with me." We talk and we sit on the edge of the tub, and that was a moment where I could totally have been ice because he definitely sounds like he's not telling me the whole story and it's in the middle of the night and not everything makes sense, but Bob and I just instinctively felt going into the scene that it's as honest as those two could be with each other in that moment. It's a very quiet moment where he needs help, and Kim is able to be there for him. The bigger circumstances don't really matter. There's no kiss, they don't even hold hands. I put [antibiotics] on his face and blow on his wounds and we sit on the edge of the tub. I thought it was one of the most loving scenes that we'd ever seen from them.

That's the kind of thing where Bob and I just knew that that kind of vulnerability from either of the two of them at this point would come from a very sweet place in the heart, as opposed to "Coushatta," when I have the headphones on and he keeps trying to talk to me. She has agreed to help him in circumstances that she finds suspicious, and she made a decision that, "I will help you and I will help you do this successfully," and on top of that, ADA Erickson has shot down Kim's negotiating, which Kim is not used to, and I think Kim does have a little bit of a problem with losing. I think she's a little bit of a freak about it. She's sitting there doing the work on this, and she's resistant to pretending this is a couple's game, like we're going to game night and we're going to win Taboo. Like, "Stop pretending this is fun. This is work and you don't get to act like it's a sexy date night. I've got to do this, go to your job."

It wasn't fury at him, as much as compartmentalizing. It's constant compartmentalizing for her. We just felt that, and the director and writer agreed. They're slippery, they're slippery moments. We'll sometimes go in and out of, "Can you be sweet for a moment?" Which we've all been there, where you throw out vulnerability for a second and when it's not met the way you want it to be met, you recoil. There's also those moments, where it goes one way and then goes the other. Again, I feel like the overall effect is real love, because we don't all stare at each other with goo-goo eyes.

The scenes a couple of weeks ago with the time jump — I think a lot of people probably expected that that might come a bit sooner. How surprised were you by how long you had to have that cast as part of your acting arsenal?

They let me know their best guess when I came back this season of how long I'd be wearing the cast. They thought probably up to episode seven, and that is in fact what happened, but I always knew that it might be longer, it might be shorter. I was prepared. Yeah, it was a long time to wear a cast, because it is a real cast. It's a real plaster cast that was applied by a paramedic two hours before I'd start work. You'd let it dry, you'd keep it on all day, you'd have it sawed off at the end of the night when everybody's done. It does not come on and off between scenes, or to go to the bathroom or to go eat. We tested other things. Some of the clip-on ones looked too bulky, some of the other ones, if you shoot in our very cool lighting and cinematic set-ups that [DP] Marshall Adams does, then the plaster looks fake if it was the plastic ones. It was all sorts of things that went into why it was best to do it, and then they checked with me for my comfort level.

It ended up being very cool, actually, that it was limiting. Not that I went into it from some absolute place of, "And now I become Kim the second the cast is on," but I 100 percent understood. Kim doesn't like to ask for help a hundred times more than I don't like asking for help, and even I was just constantly bothered by how much I had to ask somebody to help me, like help me button a blouse. And I loved realizing instantly, like, "Holy crap, Kim's having to ask Jimmy to help her get dressed every morning," and that's both frustrating and incredibly intimate, because some of these scenes, they're barely talking, but she must have asked him to help zip her pants. She had to have asked for help with all sorts of things that must have been endlessly frustrating but also a weird tether that would keep you close to the person that you're with. Having to ask somebody to drive you somewhere, trying to learn how to write notes with my left hand, which I was horrible at, and it's irritating. You can't sleep well. The times where we would be lying in bed, it would take forever to even figure out like, "What does somebody do with their arm when they're like this?" It ended up being really cool. Other than getting up two hours early, everything else was really cool.

As a last question, I think audiences are supposed to be excited when they see Jimmy behaving more and more like Saul. Now, for you, as protective as I'm sure you are over Kim, what's your reaction when you see Kim behaving more and more like Saul? Do you get worried for her? Do you get angry at her? Or do you just enjoy getting to play that side of her?

What's surprising to me, and I guess I don't judge it, I don't necessarily look at it and go, like, "Oh, wow, she's becoming bad," or anything like that, is that they feel like extensions of things that were always in her, these itches that she needs to scratch. … don't know yet if they're innate or acquired and if they're learned from other people, from whom and what do they mean? They're just puzzle pieces. I get excited about how well they write and direct and encourage me to perform on the complexities of what she's doing, and the subtle nuances of surprising yourself by your own behavior, being curious where it came from, trying to negotiate consequences and compartmentalize. It's quite the psychological gymnastics, so I get excited by that kind of stuff more than I judge the behavior or guess where it's going. I track my trajectory up to the point of wherever we're playing it and I try not to think past that.