The special guest star in the fifth episode of “Homeland’s” fifth season was the lighting director. “Better Call Saul” had great visual touches of film noir as the key players fell deeper into the abyss of suspicion, paranoia and conspiracies.

SPOILER ALERT: Stop reading if you have not seen the Nov. 1 episode of “Homeland.”

This hour saw the key characters grow more desperate in their various pursuits. That angst showed up on screen with plenty of close-ups on grim faces bathed in moody hues of blue and gray. Much of the action took place at night. It’s probably safe to say that the grime and graffiti of Berlin has never been showcased as well on American television.

A number of scenes took place in cars, and they were perfectly shot to reflect the claustrophobic experience of sitting in a parked vehicle for a long period. If this decision was a budget-conscious necessity, it didn’t really matter thanks to some smart creative choices — and one particularly amusing shot of auto-erotica. A few quibbles aside,“Better Call Saul” was nicely done all around by writers Benjamin Cavell and Alex Gansa and director Michael Offer.

There’s seemingly a shade of “Mr. Robot” in the episode as hacktivist Numan dons a face mask and lets loose a voice-modulated video inciting protests over privacy laws. Undoubtedly the similarity to the USA Network drama is coincidental, reflecting the general zeitgeist, because “Homeland” season five began lensing in Germany three weeks before “Mr. Robot” premiered in June.

The biggest reveal of “Better Call Saul” — a cool shoutout to that other show on another network — is the confirmation that Allison, the CIA’s Berlin station chief, is in cahoots with the Russian secret service. It’s the Putin mob who planted the bomb on the plane of Syria’s Gen. Youssef that exploded at the end of last week’s episode. And it’s the Russian secret service that is after Carrie Mathison, presumably because they think she’s the source of the hacked CIA documents, which we are led to believe contain something that the Russians would rather not have plastered across the Internet.

Our faith in humanity is restored as we learn that it’s not Saul who sent Quinn to rub out Carrie. That was Allison’s handiwork, doing the bidding of her Russian flame Ivan. We see that Allison is truly looking for love in all the wrong places but, again, our faith in humanity is bolstered because it turns out that Mira has left Saul (again) and thus he has not been cheating on her with Allison. Phew.

The explosion of the plane has turned Allison into an ice queen— a shift that seems to have already caused Saul to have some doubts about her, as signaled in the way his eyes bore into her in a few instances. Saul confesses to her on their drive back to Berlin from Geneva, where the Gen. Youssef coup plan literally blew up, that he’d “actually convinced myself we were going to change the world.” They share the coldest possible kiss in the car and she says curtly “don’t forget your bag.” Not the kindest thing to say to someone who has just bared his idealistic soul.

But Allison has competition in the callous department this episode from Carrie. After she figures out the Russian connection to the documents, she’s on a tear to get ahold of them. She draws her German boyfriend Jonas into the net by convincing him to bring antibiotics to help save the suffering Quinn, who took a bullet in the belly last week. She lies to Jonas in telling him that she needs the meds — and when he dutifully shows up she barely apologizes for lying, nor does she have to spell out for Jonas that she and Quinn have been more the co-workers (even if it was brief). Jonas is no dummkopf.

Yet Jonas stays at his own risk to help Quinn even after Carrie heads out in search of Laura and the documents. When Jonas calls her in a panic to tell her that Quinn is fading fast, her response? “Do what you gotta do.” That’s some self-absorption right there. Yet Jonas is just the latest in a long line of men who willingly take it in the shorts again and again to help her, as a barely lucid Quinn explains Jonas before he stumbles out of the hideout. The hideout that appears to be an abandoned church, judging by the stained-glass windows (it’s a credit to the writers and directors that they haven’t clubbed us over the head with lost-faith symbolism).

Carrie gets a hand in her hunt from Quinn’s old German-spy flame Astrid, after a testy exchange where the two don’t even try to hide their contempt for each other. Even more than Miranda Otto’s Allison, Nina Hoss’ Astrid is up to the task of putting Carrie in her place, like teasing her about a wig that looks like a leftover from the Baader-Meinhoff gang of the 1970s. But she helps out anyway because of the Quinn factor. Love is complicated.

The hacktivist protest scene outside the Russian embassy felt a little unnecessary. You could see the seams in the tightness of the focus on Carrie — the production didn’t go too big on extras and set dressing — but thankfully it didn’t drag on. Intrepid During Foundation blogger Laura does a good job of showing her struggle to contain her glee at the fact that other people are as worked up about the privacy violations as she is while she’s covering the protest. And it’s clear later when Laura has her train-station rendezvous with Carrie that she’s digging the cloak-and-dagger stuff, even if she still doesn’t like Carrie, as a blonde or a brunette. Laura gives Carrie the suggestion that will presumably be carried out next week, which is to search for the purloined documents where they were nabbed in the first place — the CIA’s own servers.

Allison’s crucial exchange with Ivan while the two are sitting in parked cars (he drives an Audi, she’s a BMW gal) in dark parking lot is full of very on-the-nose dialogue that spells out Allison’s double-agent duties. It’s a welcome relief given all the other confusing threads we’re trying to follow. Allison looks pathetic in asking Ivan to stay with her in the parking lot a little longer. The shot of the two of them passing a cigarette back and forth between the windows falls on the right side of the line between hokey and inspired. Had the cars been two-ton Buicks or Edsels, it’s not hard to picture Dick Powell and Veronica Lake playing the same scene.

By the end of the episode, Ivan’s plot is unfolding on cue. CIA chief Dar Adal thinks the Israelis planted the bomb on Gen. Youssef’s plan and Saul is under suspicion for his longtime friendship with Berlin-based Mossad agent Etai. (Last week I described that character as the Israeli ambassador — my bad.) Saul and Etai have a brief, Kafka-esque exchange that only reinforces each other’s doubts, as Etai reminds Saul that he had denied any CIA coup plans in Syria just days before. (Allan Corduner is great in his brief appearance.)

“We didn’t murder the general that you never met to disrupt the coup that you weren’t planning,” Etai tells Saul.

By the end of the episode, Saul has reunited with Carrie in the back of a cab. Quinn is lurching around the banks of the Spree river that cuts through Berlin, trying to throw himself away — in the water, in a dumpster — to help buy Carrie more time. His plan is foiled by a passerby who seems too focused on saving Quinn to be entirely innocent.

Has we ever seen Quinn in such a vulnerable place? Let’s hope the Carrie cavalry is coming soon.