Meet the ‘Better Call Saul’ Staffers Who Kept Its Story Straight

If there’s one takeaway from the moral and ideological universe of “Better Call Saul” — and its similarly meditative parent series “Breaking Bad” — it might be that details matter. Small decisions and non-decisions tend to accumulate until, to paraphrase the character Mike, who appeared in both series, we find ourselves at the end of a road, not necessarily conscious of where it began.

The force of accumulated history was baked into the premise of “Better Call Saul,” which ended after six seasons on Monday. But the creators of the show, which began its story — following the exploits of the morally-challenged lawyer Saul Goodman (Bob Odenkirk), the taciturn and principled fixer Mike (Jonathan Banks) and his fastidious drug lord boss Gus Fring (Giancarlo Esposito) — six years before the famous events of “Breaking Bad,” went out of their way to reinforce notions of predestination within the narrative. To an unusual degree, it spun a kind of clockwork ecosystem, teeming with portentous allusions, callbacks and foreshadowing that encouraged the most passionate viewers to scrutinize its every frame.

Behind the scenes, members of the show’s writing staff were no less obsessive. Ariel Levine, a staff writer on “Saul,” and Kathleen Williams-Foshee, the script coordinator, were part of what was known internally as “the brain trust” — a group of staffers who functioned as the show’s institutional memory. Working closely with a team of writers, assistants and producers — led by the showrunner and co-creator Peter Gould — Levine and Williams-Foshee maintained detailed notes on virtually every person, place, thing or event ever mentioned or implied on either the show or its predecessor.

Speaking with The Times on Tuesday, the day after the “Better Call Saul” finale, they discussed solving hard story problems (whatever happened to Saul’s ex-wives?), making the choice to contradict “Breaking Bad” and staying ahead of Reddit sleuths. These are edited excerpts from the conversation.

How long did you each work on the show and in what roles?

KATHLEEN WILLIAMS-FOSHEE I’ve been the script coordinator since Season 3 and also worked briefly as a writer’s assistant in Seasons 5 and 6.

ARIEL LEVINE And I started in Season 1 as a postproduction assistant, worked as writer’s production assistant in Season 2, a writer’s assistant in Seasons 3 through 5 and then staff writer for 6.

In the writers’ room, how did you keep track of all the history in play as you were trying to generate new stories?

LEVINE In the room, figuring out what we could and couldn’t do, or what we should and shouldn’t do, was primarily the writers’ assistants’ job. When I was a writers’ assistant, Kathleen and I would use this living document I made with every established fact or character on both “Breaking Bad” and “Better Call Saul.” So if Saul said in “Breaking Bad,” “I’ve been divorced three times,” that would be in there. Or if Gale [a meth cook in “Breaking Bad” played by David Costabile] had a résumé that appeared in one shot in one episode that said he went to a certain college, that would be in there, as well. Whenever the writers were discussing a particular character or event, we would speak up in the moment and tell everyone what is known about it.

How long is this document?

LEVINE [Checking her computer.] The final version was 52 pages.

WILLIAMS-FOSHEE It was beautiful.

LEVINE We expanded it into a spreadsheet that we called the Gillaverse Mega Timeline [after Vince Gilligan, the creator of “Breaking Bad” and co-creator of “Better Call Saul”] and then had smaller individual documents for all of the recurring characters.

How many times have you both watched “Breaking Bad”?

LEVINE All the way through? Seven. But there are individual episodes, like the one that introduces Saul, or the one that gets into the relationship between Gus and the Salamancas [collaborators in a cross-border drug cartel] that I’ve easily seen 20, 25 times or more.

WILLIAMS-FOSHEE I’ve watched it at least five times, all the way through, but probably more. When [“Saul”] was in production, we were looking at scenes from “Breaking Bad” every day.

How did you deal with story decisions that might contradict something that was established on “Breaking Bad”?

LEVINE We always wanted to be as consistent as possible, but we reserved the right to decide that something you saw on “Breaking Bad” might have been wrong. Ultimately, we chose to do what we felt would serve this story. Saul’s diploma on “Breaking Bad” said that he graduated from the University of American Samoa in 1986. But that didn’t work for the timeline of our show, so we changed it to 1998. Similarly, on “Breaking Bad,” Saul mentions a second ex-wife, and there’s a deleted scene from the show where he says he has three ex-wives, total. We actually talked about including a flashback scene to one of his previous marriages, but it seemed like too much to introduce an entirely new character. So we just had him present two previous dissolution of marriage certificates in the scene where he and Kim [Saul’s true love, played by Rhea Seehorn] get married at the courthouse.

WILLIAMS-FOSHEE It helps that Saul talks out of his ass a lot, because in a way it makes sense that not everything is going to add up. He’s just riffing constantly; that’s part of who he is.

What was the hardest needle to thread between the two shows?

WILLIAMS-FOSHEE I think the thing that took the most time and reasoning was Gus and the super lab [a giant underground meth operation that figured heavily into the plot of “Breaking Bad”]. We wanted to show how Gus and Mike came together to pull that off, but it’s clear that the lab has only recently been completed in the timeline of “Breaking Bad.” We decided that not only did we have to explain just how much time and effort went into building the lab, but that something would have to interrupt them at a certain point and essentially force them to start over.

Fans on Reddit never let any detail or perceived misstep go unnoticed. Were there any oversights that came back to haunt you?

LEVINE I think the thing that usually haunted us was stuff that was shot that we didn’t know about, or weren’t around for. Dates were a big issue. We were always shouting at production, “Please, don’t show any calendars!”