All along, certain viewers have found “The Americans” too grim to bear — too nail-bitey, too much stress on the throw pillows.

Understandable, comrade, but try filming it. The show’s intense late-fall and winter production schedule gives it a natural grimness that would be costly to replicate. Gray skies, dead leaves, bare trees and the occasional snow flurry cast a dour, ­Muscovite pall on the ­Reagan-era sunshine.

The show, set in and around Washington (and, increasingly, Moscow) during the mid-1980s, is filmed in Brooklyn, where, on a painfully frigid ­20-degree Thursday in December, a residential street has been cleared of present-day signifiers for a scene in an upcoming episode of the show’s fifth season. Cars parked along the block have been replaced by a fleet of Iacocca-style beaters, and, once the camera starts rolling, a plain brown wrapper carrying the Jennings family — covert Russian spies Philip and Elizabeth (played by the show’s co-stars, Matthew Rhys and Keri Russell) and their increasingly anxious 16-year-old daughter, Paige (Holly Taylor) — rolls up to a nondescript apartment building and parks.

It’s a big day for Paige. Her parents have decided that it’s time for her to meet their mysteriously calm but always stern supervisor, Gabriel (Frank Langella).

When making television, everything takes longer than you could ever dream it would. It will, for example, take most of a morning to shoot a scene of the family nervously getting out of the car, followed by a scene in which Philip and Elizabeth answer a few of Paige’s questions as they return to the car later. The cold makes it seem that much more bleak; the actors, attired for the early spring of 1984, look unhappy because they are.

“Paige is meant to be quite shocked,” says Rhys, who is also directing this episode. “I was hoping the extreme cold would help with that. . . . This is the kind of show where there are no throwaway scenes. I would try to give a note [to Russell and Taylor] and the two of them were like ‘F— it, it’s too cold.’ I’m cold, too, but we have to get it right.” Finally satisfied, the cast and crew return to the block of nondescript warehouses a mile away that serve as the show’s stages and production hub.

The Americans,” which returns Tuesday night, is entering what is likely to be its most crucial season, setting up its final act. Never an impressive ratings hit, the show routinely tops critics’ lists; Emmy voters aren’t as enamored. Near the end of last season, just as the show began catching on (around 1.8 million viewers followed the fourth season each week), FX announced a finish line for 2018, which gives the show’s creators, Joel Fields and Joe Weisberg, this season and next season to figure out how it all ends.

The creators’ common aim is restraint, tightening and tightening the show’s wires just to the snapping point — but rarely past it. Fields and Weisberg said that they will sometimes “unwrite” a scene in which they think the excitement and anxiety levels have exceeded plausibility. Speaking of which, there isn’t a single Vladi­mir Putin or Russian election-hacking joke that Fields and Weisberg have not heard by now, so don’t waste any more time sending them clever tweets about “Season 30” and the like. Weisberg, who says he thinks about Soviet and Russian history and current events “all the time” (his stint at the CIA in the early 1990s means that each “Americans” script must be submitted to the agency’s publications review board for approval), isn’t interested in drawing modern parallels. This show is resolutely about three things: the Cold War, the ’80s and, most of all, a troubled marriage.

“In Season 1, there were fights and guns and explosions and I thought, okay, that’s fun, but what I love more is that I haven’t held a gun in two seasons,” Rhys says. “It’s almost all about the relationships, and if you can maintain a show that has that kind of tension based on those things — it’s hard to do and so much better.”

On orders from the KGB, Gabriel (and his colleague Claudia, played by Margo Martindale) routinely send Philip and Elizabeth on risky undercover schemes and acts of breaking and entering that bring the story to the brink of panic. Besides the fact that Paige now struggles with the secret that her parents aren’t merely the workaholic proprietors of a ­Dupont Circle travel agency, the most pressing issue is the family’s overly friendly, across-the-street neighbor in Falls Church, an FBI agent named Stan Beeman (Noah Emmerich), who is more determined than ever to root out the spies in his midst.

“Nothing scares those two,” Claudia tells Gabriel in the Season 5 opener.

Everything scares those two,” Gabriel replies.

(Patrick Harbron/FX)

(Patrick Harbron/FX)

And so “The Americans” has become a volcano that’s way overdue for disastrous eruption. Like that copy of “Leaves of Grass” in Walter White’s bathroom (“Breaking Bad’s” unforgettable pivot point), this, too, feels like the season in which “The Americans” will have to crack itself open. A few years ago, when they were desperate to get people to watch the show, Fields and Weisberg could be quite chatty about where they thought the story was headed, along what sort of timeline. Now? Forget it. Story arcs are top secret and kept in a master binder everyone’s heard about and no one gets to see, not even Russell and Rhys.

“I only know what’s happening to about now, and we’re on episode six and seven,” Rhys says, taking a lunch break. “I think they’re wise to the fact that I have a mouth like a drunken sailor and that I would shoot it off to anyone.”

“Do you know?” Russell asks me, “Did they tell you anything? No? Oh well.”

She has changed from her ’80s garb into a faded blue jumpsuit, topped off with a huge Mongolian wolf-fur hat that towers a foot above her head and that on just about anyone else would elicit guffaws. On her, it seems fetchingly exotic. It’s one of her most treasured possessions — Rhys brought it to her in 2014 after he made a horseback trek in Mongolia.

There’s something to be said for a charming Welshman who brings his co-star a prized Mongolian wolf hat. You’d swoon, too. Not long after the show first garnered high praise, the celebrity-news media started covering Russell, who turns 41 in March, and Rhys, 42, as an item. A couple of years on, parts of Season 4 were shot from angles that hid her pregnancy. Their son, Sam, was born last May, and the couple managed to keep the vital statistics out of People, Us Weekly, et al. for several weeks. Sam is Rhys’s first child and Russell’s third.

Most of this has been played in the lowest key available to today’s celebrities. “I think most of the paparazzi we get is falloff,” Rhys says. “They’re waiting for someone bigger and then we happen to just walk by.” Heightened attention brings about a necessary guardedness that echoes some of what Philip and Elizabeth would do to protect their own kids. When photographers were trying to get a photo of their baby’s face, “it was the most primal I’ve ever felt,” Rhys says.

“Do we relate to it in that way?” Russell wonders. “It must filter in somehow. What you’re making me think about more is that, of the two of us, I naturally am the more private one. Maybe I always was . . . because I did that TV show [the late-’90s collegiate drama “Felicity”] when I was very young and I was really uncomfortable with [celebrity], so I tend to be very private and closed down about all sorts of things, versus he’s much more gregarious and in the world and talking to every single person.”

Both Russell and Rhys say they used to talk much more about Philip and Elizabeth (“Phil ’n’ Liz,” as Rhys calls them), often teasing each other about their characters’ faults, which could lead to real arguments about their essential points of view.

“You mean how Phil is infinitely more human?” Rhys asks, smirkingly. “We do argue about them, yes, often starting out with a little mocking debate — she’ll say, ‘Phil’s so weak’ and I’ll say, ‘Liz is so cold,’ and it leads sometimes to a serious discussion about who’s the stronger or more dynamic.”

“We never planned in the beginning how [Philip and Elizabeth] were going to react or behave with one another, not really,” Russell says. “You’re like animals in a cage together — you work well with some and you don’t work well with others. And here it just worked. We trust each other. Or we don’t, some days.”

At this point, Rhys says, there’s less arguing about who Phil ’n’ Liz are and more talk about how they feel. “I go so far as to say ownership,” Rhys says. “I own Phil Jennings. I’m the person who thinks the most about Phil Jennings. No one else.”

This season opens with a nifty addition to Phil ’n’ Liz’s endless reserve of wigs and disguises — this time they’re posing as an airline pilot and flight attendant who are married and based in D.C., and whose adopted Vietnamese teenage son (another spy) befriends the dejected son of a recent Soviet émigré who may or may not be helping the United States contaminate the U.S.S.R’s wheat supply. Befriending this man and his family entails another long con for Phil ’n’ Liz, whose entire lives are a lie.

As it happens, around the same time frame in which this season plays out, the author and psychiatrist M. Scott Peck published “People of the Lie: The Hope for Healing Human Evil” just as his earlier book, “The Road Less Traveled,” was becoming a big bestseller.

Where “The Road Less Traveled” explored such warm subjects as fulfillment, love and grace, “People of the Lie,” released in late 1983, made a darker, more disturbing case for the notion that we are surrounded in our everyday lives by a banal yet pernicious evil that quietly consumes our neighbors, friends, family and co-workers, causing them to live deceptively. Peck, who died in 2005, believed that evil should be considered a mental illness, and his pop psychology is just the sort of fleeting yet perfect period detail that would show up in an “Americans” episode.

At the time, readers of “People of the Lie” began seeing evil and lies in even the most normal-looking circumstances. As a churchy teenager, very much like Paige Jennings, I remember picking up on the subtlest, contradictory cues while observing the adults in my life, which sometimes included my friends’ parents — their quick tempers, the arbitrary rules, the frosty silences or hearty laughs (one never knew which to expect), the sudden reprimand for sharing innocuous household details with friends on the phone. A teacher assigned “People of the Lie” and reading it gave me the creepy idea that many adults were pretending to be something they weren’t. If Paige and I had been friends (as we surely should have been, in that parallel 1980s that holds all of Generation X in its nostalgic grip), Philip would surely have snapped my neck and driven my body out to the NoVa woods somewhere.

I flash back to “People of the Lie,” a book I haven’t thought of in years, while getting a tour of the chilly interiors of the Jennings home and thinking of all the lies kept here — the living room, the kitchen with its geometrically garish wallpaper, the random cassette tapes in Paige’s bedroom.

Finally there’s Phil ’n’ Liz’s bedroom, in its mauve and wicker middle-class splendor, with the en suite master bath and its rust-orange decor. It’s just a set on a TV show, but because of what Russell and Rhys have created together — because of what viewers have seen here — it gives off a musky intimacy.

And because it’s “The Americans,” there’s also a whiff of doom. Things are going to get messy for Phil ’n’ Liz. Viewers will soon have to reconcile the concern we have for them with the fact that they’re “the enemy.”

Once she understood that Elizabeth was more than just a coldhearted communist on a lifelong mission, Russell says she decided to ride it out and see where it goes.

When first offered the part, she kept saying no, “Until I saw how interesting the marriage was,” she says. Even story twists she initially didn’t like turned out well, so she quit worrying about the Jenningses’ ultimate fate. There was a panel discussion with the cast and showrunners last October at New York’s 92nd Street Y, at which Russell mused aloud about an upbeat outcome.

“I still always wonder if I can say this or not, but there has to be a possibility of a turn, right?” Russell says. (Yes, of course. Defection! Safety! God bless America!) “And I look over at Joe [Weisberg] and he gives me a look and just says nope. . . . So now I really have no idea — and I’m okay with it.”

The Americans (one hour) returns Tuesday, March 7 at 10 p.m. on FX.

https://www.washingtonpost.com/entertainment/tv/how-matthew-rhys-and-keri-russell-learned-to-stop-worrying-and-love-their-characters-chilly-fates/2017/03/01/169b5b38-f938-11e6-bf01-d47f8cf9b643_story.html?hpid=hp_hp-top-table-main_stuever-americans-0935%3Ahomepage%2Fstory&utm_term=.03f8494a78f1