Jimmy McGill (Bob Odenkirk) and Kim Wexler (Rhea Seehorn) are living separate lives together, and Better Call Saul is using every trick in the book to prove it.

"Something Stupid," the seventh episode of the show's outstanding fourth season, kicks off with a musical montage set to the song of the same name. Made famous by Frank and Nancy Sinatra, it's a meticulously constructed tune, its verbose lyrics and complicated two-part harmony embodying the fear of being really close to someone but holding back because you're worried about revealing you're more into them than they are into you. (It's made slightly awkward by the fact that Frank and Nancy were father and daughter, but this is the Nicole Kidman/Robbie Williams version, so no harm done.) It's one of the most astute soundtrack selections in the history of the BCS/Breaking Bad universe, and that's saying something.

Killing Kim Would Be the Biggest Mistake Better Call Saul Could Ever Make

The imagery accompanying the song is equally effective. Using a split-screen effect — one that takes a few seconds to get going so that at first all you see is half a screen before the second image kicks in — it chronicles Jimmy and Kim's daily routine. They brush their teeth, eat breakfast, go to work. Kim moves into her new office as a partner in the firm of Schweikart & Cokely; Jimmy plays handball against the window of his empty cellphone store. Kim racks up commemorative trophies for Mesa Verde branch openings and clients for her sideline as a pro bono public defender; Jimmy piles up visits to his parole officer and stacks of cellphones for sale to his less-than-legal clientele.

But the split screen stays in effect even when the two are right next to each other, eating dinner or getting into bed. Sure, Jimmy might reach across that black bar to pour Kim some wine, or Kim might stretch a leg across to drape it over Jimmy as she sleeps, but it's always there. And in the end, after the song fades away, Kim's side of the split screen fades away too, leaving Jimmy alone in the dark. Writer Alison Tatlock and director Deborah Chow conveyed the slow death of a relationship in the form of a music video, basically, and it's beautifully sad to watch. A later scene, in which Jimmy wows everyone at Kim's company party with his gift of gab except for Kim herself, only underscores the initial point.

The opening sequence serves another purpose: It conveys the passage of months in just a few minutes. The cast on Kim's arm comes off by the song's end, for example — an echo of the progress Hector Salamanca (Mark Margolis), whom we last saw unable to lift a finger, is making as he comes back from his stroke. Now he's well enough to sexually harass a nurse by knocking over a glass of water with his pinky so she'll be forced to bend over and clean it up, allowing him to check her out. Of course, this incident also lets Gus (Giancarlo Esposito) know that Hector's (Mark Margolis) grotesque mind is back up and running, even if his body is not cooperating; with barely concealed joy that's chilling to behold, the Chicken Man orders his treatment stopped, trapping his arch-enemy in the prison of his own body before any further progress can be made.

Time has passed for Mike (Jonathan Banks) as well. When the action picks up with him and his crew of German demolition and construction experts, they've clearly been at it a long time. The show employs one of the same tricks, in fact: Our reintroduction to the group is set to yet another song played in its entirety, this time Burl Ives's charming fantasia of a world without grinding poverty or vindictive police, "The Big Rock Candy Mountain." Once again, the song concludes before the final shot of the sequence does, drawing our attention to the silence and the passage of time .

As with Jimmy and Kim, tension and dissatisfaction is running high. These guys have been cooped up so tight for so long, shuttling from a hangar-sized warehouse to an underground bunker and back, that they're starting to get both snippy and sloppy. When one of the workers backs a vehicle into a load-bearing column, knocking it down, another one has to be physically stopped from assaulting him.

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The attacker is Kai (Ben Bela Böhm), the loudmouth who drew Mike's attention last week. This time around he's badmouthing Mike in German; it's a language Mr. Ehrmantraut is picking up well enough to know when he's being insulted, no matter how the bossman, Werner (Rainer Bock), translates the words. Together, Werner and "Michael," as the project leader affectionately calls him, agree that "the boys" need some R&R — fresh air, sunlight, and other more intimate delights are implied. If you think this will end well for Kai, I've got a van full of cellphones to sell you.

Speaking of which, all good things must come to an end, and Jimmy's phone dealership is one of them. When he's approached by a plainclothes detective who tries to get him to stop selling to drug dealers, his muscle, the taciturn pickpocket Huell Babineaux (Lavell Crawford), thinks he's being hassled by a customer and whomps the guy on the side of the head with a bag full of sandwiches. This is enough to send poor Huell to the hoosegow for over two years...unless Jimmy can persuade Kim to intervene before Huell just skips bail and makes a run for it.

Kim agrees, despite the fact that a career criminal isn't her usual kind of client — and that her boyfriend has been running this business behind her back all this time. The episode ends on a strange, quiet cliffhanger, as Kim goes on a school-supply shopping spree, begging Jimmy over the phone to stop whatever shady plan he had in motion to help Huell triumph over the cop because she has "a better way." Better for Huell and Jimmy, maybe. Better for Kim? Hard to imagine.

Sure, you might miss the steady threat-level escalation, both physical and moral, of the season's opening half. But do you feel any less tense or anxious or nauseated watching this thing? I sure don't! Watching Kim Wexler zip around an office supply store picking up multicolored magic markers is a far cry from, say, Howard Hamlin (Patrick Fabian) melting down because he blames himself for his sick friend's suicide, let alone Nacho Varga (Michael Mando) being forced into indentured servitude and nearly killed by Gus Fring's goons.

But you can see on her face, courtesy of the typically powerful wordless performance abilities of Rhea Seehorn, that she's planning to do something she's confident a) will work and b) shouldn't be done. I don't want Huell to go to jail, but I don't want Kim to offer up her soul as collateral, either.

It comes down to what the prosecutor angrily tells Kim during their argument over whether Huell is being dealt too stiff a sentence: The guy's only supporting eyewitness is "a scumbag disbarred lawyer who peddles drop phones to criminals," a.k.a. James McGill. Kim all but runs out of the empty courtroom when this happens, and you can see in her eyes that she fears the D.A. is right. Maybe that is what Jimmy — the man with whom she shares an apartment if not quite a life any longer — really is. And if that's the case, what does that make her? An attorney, or an accessory?

Better Call Saul airs Mondays at 9/8c on AMC.