Last season of “Better Call Saul” ended in flames, literally, as Chuck McGill (Michael McKean) set his home on fire, killing himself in a final act of desperation. The impact of his suicide will ripple through season 4, which debuts August 6 on AMC.

Showrunner Peter Gould tells Variety it’s an “earthquake” in Jimmy’s (Bob Odenkirk) life, that kicks off a deeper season than we’ve seen from the show before.

The season also delves further into the prequel’s “Breaking Bad” roots, a shadow that’s long lingered over the drama. The casts of both shows intermingled at Comic-Con last month, when  “Breaking Bad” held a 20-year reunion panel and “Better Call Saul” screened the season 4 premiere for fans.

“Seeing them all together at the same time, I got a rush just like the fans did,” admits Gould. “Just seeing everybody together makes me want them all. I’m greedy. I want them all in Albuquerque on our set again. The problem is always having story that’s worthy of those folks, because we try not to be arbitrary, we try to exercise self-discipline. If I were just to cast actors who I’ve enjoyed, I love and I enjoy working with, we’d have a lot more characters.”

Here, Gould tells Variety what’s in store for the rest of the season, including Kim and Jimmy’s “greatest scam ever,” the “stormy waters” ahead for Mike, and yes, more crossover with “Breaking Bad.”

Going into this season, what are some of the themes that you wanted to explore?

The big thing really that we had to deal with this season was the question of how does Jimmy McGill mourn for Chuck? I will say that killing the character of Charles McGill was maybe the most difficult decision I’ve ever been a part of in the writer’s room. Everyone on the staff got sick of hearing me whine about, Do we have to do this? Is there another way? But once we knew that that was the way forward, we also knew that this was going to be an earthquake in Jimmy’s life. Not just how mourning works or how loss works, but how it works for this particular person and with all the complications and the depth in his relationship with his brother. Because of the loss of Chuck, this season goes even deeper than any of our other seasons. There’s something very human, very emotional, sometimes tragic, sometimes strangely funny about the way that Jimmy mourns Chuck and the way Jimmy proceeds after this huge loss.

He’s already been on the path to Saul, but how much does this propel him further down that road?

I think it develops through the season. This season is the season where you understand that Saul Goodman is a choice and that Bob has said, to me Saul Goodman is a punk rock choice. It’s a rebellious choice and I think you start to understand this this season. Why Jimmy McGill, who is a goodhearted guy, why he makes this choice to cut himself off from himself to assume this very different mask in front of himself. I think we start understanding Saul Goodman in a different way, too. So it’s absolutely this season is the one. We see a couple of different versions of Saul Goodman this season, and each one of them is, in its own way, kind of delightful, but also kind of tragic.

What’s the role of Kim (Rhea Seehorn) in all of that? Does she go along that ride with him or did she resist it as she sees him changing?

One of the things I’m so proud of the character of Kim Wexler and Rhea Seehorn’s performance. The relationship between Kim and Jimmy is not straightforward. She’s not his conscience. She’s not the boat anchor around his ankle that keeps him from doing what he wants to do. A lot of what Jimmy does this season is because of what he perceives to be his relationship with Kim. Jimmy McGill, who we’ve known for three seasons, has two people who were absolutely at the center of his universe, Chuck and Kim, and now he’s lost Chuck. And so his relationship with Kim is really very central at this point. And Kim feels the pressure. Kim, on the other hand, also has an independent life of her own.

One of the things that I find I find so appealing about Kim and about the relationship between Kim and Jimmy is that Kim is not in the relationship because she needs Jimmy. She’s in that relationship because she wants to be in the relationship. She loves Jimmy, but she’s not needy for Jimmy. There is an independence to Kim that Jimmy doesn’t always interpret to its best advantage. I think he loves her for her independence. But I think that his interpretation of her independence sometime causes him to do things which are not in his best interest is she. Does she part ways with him? Sometimes. But the complexity is that sometimes Jimmy and Kim are at their best and most passionate when they are scamming together. And this season we see Kim and Jimmy’s greatest scam ever. It doesn’t come until a little deeper into the season but I think it’s one of the most fun things that we’ve ever done. It makes you fall in love with these two all over again.

The other characters, like Mike (Jonathan Banks) and Nacho (Michael Mando), have mostly existed on parallel paths. Are those paths ever going to intersect the season? 

They intersect sometimes and sometimes they continue in parallel. It’s interesting because I would’ve never consciously shaped the show along parallel lines. It’s not something we necessarily set out to do, but it has to do with who the characters are and their choices. Having said that, you can feel the worlds overlapping in a new way this season and you can also feel the approach, or at least on the horizon, the events of “Breaking Bad” start to make more sense as the season proceeds.

You’ve said this season also intersects more with the world of “Breaking Bad.”

You will see some locations and characters who you haven’t seen since “Breaking Bad.” One of the things that we have so much fun with in this show is our ability to go back and forth in time. And so far we’ve seen Slippin’ Jimmy back in Cicero, Illinois; we’ve seen Jimmy in Albuquerque; we’ve seen Gene in Omaha. But there’s nothing to prevent us from also seeing Saul Goodman during the course of “Breaking Bad.” And that’s something that we’ve always been very excited about.

We know that we’re going to meet Lalo. Why was that the one character that we know of so far that you wanted to bring back?

This is not something that happens right away. But I will say Tony Dalton comes in as Lalo, who was of course mentioned on “Breaking Bad” but never seen. In fact, I wrote that episode in which Lalo was mentioned. And I remember going back and forth with Vince about what the names are of the guys who Saul Goodman’s afraid of, When Jesse and Walt have Saul at gunpoint over in front of that open pit, Saul assumes that they are cartel representatives. He starts yelling in Spanish and English and saying that he’s a friend of the cartel and he’s calms down when he realizes that they’re not from Lalo. There’s nothing to do with Lalo. So we’ve always wondered, ever since the beginning of the show, who is Lalo? And in fact, nobody’s been wondering that more and more vocally than Bob.  I can’t tell you the number of times Bob has brought up, Are we going to see Lalo? When are we going to see Lalo? We have to see Lalo! And so Bob kept the character in mind for us. And this season finally, he makes an entrance and I think he’s pretty unforgettable. He’s a whole different kind of cartel boss, that’s for sure.

What’s in store for Mike this season? How enmeshed does he get in Madrigal?

You know, we started off the show with two huge problems. How does Jimmy McGill become Saul Goodman? And of course we thought that would take us 10 episodes and it’s taken us a hell of a lot longer. But we also had the question about Mike Ehrmantraut, who we first meet on the show working in that parking booth, and we know that he is a former cop, maybe a cop who was on the take but a cop nonetheless. And so we set ourselves the problem of how he becomes the right hand man for Gustavo Fring (Giancarlo Esposito). And to make it even more difficult, Mike is not a materialistic guy. We’ve seen that he lives in pretty modest circumstances. He drives old cars. He certainly cares a lot about the future of his granddaughter. But he’s not a materialistic person. So why is he working for Gus Fring? It may seem the two men came to an agreement last season, but really all that happened was that Mike asked Gus for a favor, which was to launder the money that he had stolen from Hector Salamanca. And that was definitely the first step in a dance with the devil. But this season we’ll find out that the relationship between Gus and Mike has not always been smooth. And there are definitely some stormy waters ahead.

And certainly for Nacho, too. It feels like from that finale, Gus Fring knows that he played a role in Hector’s stroke.

I am fascinated by Nacho and I’m fascinated by Michael Mando’s performance as Nacho. Nacho is a guy who is, I think in his heart would be pretty happy not to be in the drug business right now, but it’s not so easy for him to get out. And it seems like every move he makes just makes things worse. He goes from the frying pan to the fire. It’s one thing to have to work for Tuco Salamanca, he seemed to handle Tuco pretty well. But boy, nobody handles Hector. And just when it seems like he’s out from under Hector, here comes Gus Gring and Gus Fring iis a very, very formidable guy. He’s not someone you want to cross and Nacho is not necessarily on Gus’ good side. We’re going to see Nacho squeezed like he’s never been squeezed before. And Michael Mando has some of his greatest scenes yet.

How is Gene now and are we going to get to spend more time in his world?

I love Gene! Gene is the cockroach that survives the nuclear war. Gene is a coward, which is interesting to me because we’ve seen a lot of stories about people who physical heroes, and Gene is a coward. He’s a survivor and he is completely shut down. I love the way Bob plays this guy. He’s so subtle and dimensional, so suspenseful. Bob makes reciting a Social Security number, something that we’ve all had to do a million times, into a suspenseful, almost terrifying moment. He may be wearing glasses and a mustache, his hair may be very different but Gene wears the same face that Saul Goodman wore and that face was all over Albuquerque television and billboards for years.

This show is like a Rubik’s cube. We know so much about these characters and things that happen to them. But Gene is really a wide open book. The wonderful thing about Gene though, is as closed down as he is, there are still all the colors of all the people he had been before.He’s trying on all these different masks. He’s added all these layers, he’s showing all these different sides and I think he’s on a search for his true self, but it’s turned very, very lonely and in some ways, maybe the way we find our true selves is through other people. And it’s a very tough thing because Gene is truly alone, as alone as a person, can be a modern society. I think.

Is that a way that the show might possibly continue? Could there be a version that exists more in Gene’s world?

I think so. It’s an interesting question because with “Breaking Bad,” we had this end point. We knew Walter White was going to die. Walter White knew he was going to die. And so there was a tragic dimension to that show. There is a tragic dimension to this show, too, which is that a man who we like and who is struggling loses his struggle with his best self and becomes Saul Goodman. But there is a ray of light too because he doesn’t die. There’s still more life to be had and so it gives our story a very different shape then that fascinates me.

Does that make the show easier or harder to do narratively?

They’re just two different animals. To the outside viewer, it may seem like just a continuation of what we did before, but we really see them as very different shows. And I think really the core is our lead. I think Jimmy McGill is a very different person from Walter White. Walt is a fascinating character. He is somebody who I think is ultimately frightening. You’re kind of fascinated by the power of his rage and Jimmy is maybe a little bit more human. If you beat Walt up, the first thing he’s going to think about is how he can get back at you.

Jimmy takes something very different from his beatings. It also makes the beatings both literal and metaphorical. It’s the knocks that he takes in life he interprets differently and he does different things with them. And I will say with both shows, the greatest challenge for us has always been to understand the character. When we get stuck on both shows, it’s always because we haven’t understood something about our character, that the way forward is not clear because there’s something we’re trying to get the character to do something that he or she doesn’t want to do. We also have learned now over 11 years that our audience seems to be made up of a bunch of geniuses. We found that we can allude to things, we can suggest things and the audience will pick it up right away.

What’s the one question fans should be asking ?

I think the biggest question should be what’s going to happen with Jimmy and Kim. I get a lot of questions about whether Kim is going to die. Which is interesting to me because it tells me that people really care about her. People should be watching that core relationship. And watching Bob and Rhea together, I find it very rewarding. It’s a multidimensional, very adult relationship that these two characters have and that Bob and Rhea have enacted, brought to life. They’re just fascinating together, but I have to say I’m worried about them.