WHAT: "Better Call Saul," whose season 4 premieres at 9 p.m. Monday on AMC

WHAT IT’S ABOUT: In the closing minutes of the third season of “Better Call Saul,” Jimmy McGill’s (Bob Odenkirk) brother, Chuck McGill (Michael McKean), lost his mind while chasing down the source of some errant electricity in his house. (As you recall, Chuck had a rare syndrome, effectively making him hypersensitive to electromagnetic radiation.) While rhythmically pumping his left leg against a table, he knocks over an oil lamp that sets the house on fire. Chuck perishes in the blaze. The fourth season picks up as Jimmy starts to reimagine a future without Chuck — or the law. In fact, a lawless future begins to assert its appeal. Meanwhile, law partner and lover Kim Wexler (Rhea Seehorn) attempts to make sense of the fallout from Chuck’s death. Then, there’s this: Hector Salamanca’s (Mark Margolis) stroke at the end of the third season opens up a new world for Albuquerque’s fried-chicken — and once and future meth — king, Gus Fring (Giancarlo Esposito.)

MY SAY: With the end of “The Americans,” “Better Call Saul” now seems like the last remaining vestige from TV’s current golden age. While that’s not technically true — we hear “Game of Thrones” will return next year — the first three episodes of the fourth season reliably, predictably, and easily make that case themselves. The power and glory fans have come to expect is all here, with some added bonuses, including a richer, deeper and more layered Nacho Varga, the Salamanca heavy played brilliantly by Canadian actor Michael Mando.

But of all these bonuses, Seehorn’s performance merits the most prominent mention. Kim was always vital to the success of this series, for through her the humanity of Jimmy was refracted. Her grounding grounded him, her decency made Jimmy more decent.

But in the fourth season, Kim breaks out. At moments over these three episodes, her performance is so powerful and so memorable that the formula is almost scrambled, so that this is no longer the Jimmy show but the Kim one. She’s allowed a depth of emotion too that Jimmy’s not allowed — ever — even in the wake of his brother’s death. Recall Chuck’s last words to Jimmy in the third-season finale — “I don’t want to hurt your feelings, but the truth is, you never mattered all that much to me.” In that instance, something breaks in Jimmy, but this season, it’s left to Kim to emotionally explore what that wreckage is.

She does (and how) but a sadness comes with the performance because we know there’s no sequel for Kim, no “Breaking Bad” callback. “Bad” is all in the future, and she is all in the past. Her future absence makes Jimmy and, of course, Saul, more tragic.

And speaking of callbacks, “Saul” begins those in earnest this season too. These aren’t cheapo cameos to remind us of the show’s ties to one of the greatest series in TV history. Each is organic to the story, each about character genesis. Of more importance, each is electrifying: Gus’ stone-faced enforcer, Tyrus Kitt (Ray Campbell) is back after a quickie re-entrance in the third. The Salamanca “cousins” — Leonel (Daniel Moncada) and twin bro Marco (Luis Moncada) — who were quite possibly the most fearsome figures in “Bad” history, have also returned. Lydia Rodarte-Quayle (Laura Fraser) is back, and we learn more about the dynamics of her strange ties to Gus’ new security chief, Mike Ehrmantraut (Jonathan Banks).

There’s another huge callback, and to say who would enter spoiler territory (but be certain to stick around for the closing minutes of the third episode). While not of the magnitude of Gus’ re-entry last season, this one will still leave you wondering: how long before Jesse (Aaron Paul) or Walter (Bryan Cranston) drift into Jimmy’s orbit?

“Saul,” like “Bad,” is a series about catalysts — both human and chemical — and the catalyzing event in Jimmy’s life has now occurred. Chuck’s death has hollowed him out and unleashed the character flaw that was always there. The flimflam man with the fast quip is still there, but the conscience and moral compass have receded. They’re not at a vanishing point yet — that comes with “Breaking Bad” — but the fall has begun, and it won’t stop until Jimmy/Saul is swabbing those floors in a Cinnabon in Omaha.

BOTTOM LINE: The precision of “Saul’s” craftsmanship — writing, direction, acting, and all the way down to craft services, for all I know — makes this the best series on TV. And there really is no contest.