By Dan Snierson
March 30, 2015 at 12:00 PM EDT
Ursula Coyote/AMC

[SPOILER ALERT: Do not read this story until you watch “Pimento,” Monday’s episode of Better Call Saul.

For years, Jimmy McGill had looked up to his older brother, Chuck, and had often let him down. But then one day, finally, the struggling, hustling lawyer literally pieced together the case of his career—a lawsuit against the elderly swindling Sandpiper Crossing assisted living facility—and Chuck, the gifted yet sidelined attorney, gave him his sibling seal of approval. The McGill boys’ joining of legal forces would be a brief union, though, as Howard (Patrick Fabian), the well-appointed, smug lawyer who was a partner with Chuck (Michael McKean) at Hamlin, Hamlin, & McGill, told Jimmy (Bob Odenkirk) that he was highly interested in bringing the case—but definitely not Jimmy—into their high-end practice.

But as it turned out, Jimmy’s biggest obstacle at HHM was actually a different partner: Chuck. Yes, the brother who had always bailed him out of trouble, the same brother who was hobbled by an electricity-fearing mental illness that Jimmy was trying to help him power through, had shocked him to his core. When Jimmy confronted Chuck about his betrayal—pretending to be taken aback by Howard’s rejection of Jimmy when he in fact had orchestrated it with a late-night call—Chuck lashed out and wounded his younger brother, telling him that he was not cut out to be a lawyer: “Slippin’ Jimmy with a law degree is like a chimp with a machine gun.”

It was a devastating development for The Man Who Will Become Saul, and one that took even the show’s writers by surprise when they brainstormed “Pimento,” the second-to-last episode of Better Call Saul‘s first season. “When we started the show and thought about Chuck, he was somebody who was fundamentally helpless at the moment,” executive producer Peter Gould tells EW. “He was somebody who Jimmy had to take care of. And part of the reason we loved it was because it humanized Jimmy. We thought the connection between the two brothers gave us an insight into Jimmy’s heart, to understand how and why he became a lawyer. Once we saw Michael McKean play Chuck, he brought some colors to it that I don’t think we were really expecting. Chuck, as Michael plays him, is someone with a tremendous sense of righteousness, sometimes self-righteousness. He’s also a guy with a lot of pride. And as we were working our way through the season, we started talking about how Chuck really feels about Jimmy.

“Part of the reason Jimmy’s always gotten into trouble is because he could never equal Chuck,” Gould continues. “Chuck was always the good brother. But from Chuck’s point of view, Jimmy was the one who got all the attention. Jimmy was the kid who would make everyone laugh with a joke. And Chuck, for all his ability and all his brains, really doesn’t have the common touch. And we realized—and it came as a shock to us—that on some level, Chuck is jealous of Jimmy. And that Hamlin wasn’t the problem for Jimmy, really; it’s Chuck. Chuck does not want Jimmy in his law firm. It makes Chuck deeply uncomfortable for so many reasons—some of them legitimate—to have Jimmy be a lawyer at his level. And one of the things I love about the scene at the end of episode 9 that [co-executive producer] Tom Schnauz wrote, and that Bob and Michael played, is that Chuck is not all wrong. Especially those of us who watched Breaking Bad know that there is an element of truth to what he says: ‘The law is sacred. If you abuse that power, people get hurt. This is not a game.’ And that brings up the question: How much is that a self-fulfilling prophecy? Does Jimmy act out because deep down, he believes what Chuck thinks of him?”

While you meditate on those issues, Gould volunteers this hint about the brothers’ relationship moving forward. “It is fair to say the gloves are off,” he says. “These guys understand each other. They are no longer hiding who they are from each other. This revelation is going to change everything between them.”

Exactly how it alters their dynamic and what consequences follow in next week’s season finale (and beyond) is something that the writers wrestled with for a long time before the lightbulb illuminated. “We found that this guy does not react to information and to new turns the way we always expect,” he says. “Jimmy has had incredible resilience, but this is also a guy who really feels it when someone he’s close to hurts him… Episode 10 takes the show in a left turn that I don’t think any of us were expecting in the writers’ room but now feels like the only thing that could have happened.”

As for Jimmy’s future fixer, Mike? He broke bad in his new home of Albuquerque, taking up a veterinarian on his offer to provide some lucrative dirty work. Mike (Jonathan Banks) was motivated not by greed, though, but by the guilt and desire to provide for his cash-strapped daughter-in-law, Stacy, and granddaughter Kaylee. (Taking guns from an obnoxious thug and teaching him to shut the hell up the hard, windpiped way is just a perk that comes with the job.) “Mike came to Albuquerque because the only people who matter to him are his granddaughter, Kaylee, and his daughter-in-law,” says Gould. “But the truth is, in Mike’s mind, it’s his fault that his son died. And that is a sin that he cannot wash from his soul, no matter what he does. I don’t want to sound too religious, he believes he’s already damned. There’s no way he can ever make up for what he’s done. And the fact that his daughter-in-law has allowed him back into her life and his granddaughter’s life, that’s what is keeping him going. What happened in episode 8 was Stacy said, ‘You can never it make up,’ but maybe there is something that she needs. And what she needs is money, and he sure as hell knows how to make that. But don’t forget that Mike, in episode 9, doesn’t even carry a gun [to the protection job]. He is playing it as safe as you can in that circumstance. And we’ll see how long he can continue doing this kind of work without carrying a gun and without getting terribly violent.” Shall we guess somewhere between Pretty Soon and Not Terribly Long?

Come back to later this week for a few tantalizing teases from Mr. Gould about Better Call Saul’s season finale, which airs next Monday on AMC.