Spoiler Warning: Do not read on unless you’ve seen “The Americans” season 3, episode 7, titled “Walter Taffet.”

Noah Emmerich has been angling to direct an episode of “The Americans” since season one. The thesp, who plays FBI agent Stan Beeman on FX’s Cold War drama, asked the showrunners early in the run what it would take for him to get to try his hand behind the camera.

They told him to take advantage of being on the show and soak up every aspect of production: From the initial production meetings all the way through the editing and sound mix. “Any time I had time off as an actor I would hang out and observe what I could,” Emmerich says. By the end of season two, Emmerich knew he had the gig.

He didn’t know it would be such a doozy of an episode. Among the events of tonight’s “Walter Taffet”: Philip (Matthew Rhys) finally tells Elizabeth (Keri Russell) about his long lost son; Sandra (Susan Misner) asks Stan for a divorce; Stan’s hotshot colleague Agent Aderholt (Brandon J. Dirden) discovers the bug in the office of Agent Gaad (Richard Thomas); and Martha (Alison Wright) suddenly realizes that her husband Clark (Philip in disguise) may not have had the best intentions when he asked her to plant that same bug.

Variety spoke with Emmerich about the various challenges of doing double duty on such an incident-packed episode.

Was this episode picked specifically for you to direct?

The funny thing about a series is you have the schedule for shooting long before you have the actual content of what you’re shooting. We knew I’d be directing episode seven at the beginning of the season but it had yet to be written. It’s sort of a pot luck. It was the first episode back from Christmas break, which worked out well for me; I had the time over the break to prepare. When you get the script you hope it’s one you connect to and fits your sensibility. I got lucky, the script was phenomenal.

It’s a real showcase for Alison Wright as Martha. She has to express so much without dialogue.

It’s a seismic shift in (the Martha and Clark) relationship — this woman has been so blindly trusting and loving of this man who is so aloof and mysterious. Then this thing happens at work, and this subconscious fear that I’m sure existed in her somewhere — maybe we know everything all the time but we don’t connect to it — what happens at work makes it impossible for Martha to go back and look at Clark in the same way. I’m such a fan of Alison Wright. She has a very expressive quality and nails those scenes.

Did you work to modulate exactly how suspicious Martha is with Clark?

It can’t be absolute and it can’t be nonexistent. It’s almost like when you think your spouse is having an affair and you convince yourself that you’re crazy, but then you get one piece of evidence that’s enough where you can no longer think it’s just in your head. It’s just sort of hard to look at them. You don’t want to be right. And you don’t want to find out that you’re right. But you also don’t feel that you’re wrong. You’re stuck in this weird paralyzed state. Alison and I had a conversation about that and how she can’t really look at him, she can’t quite hold eye contact with him. It’s a very fine place to center that on, which I think she did brilliantly. You really feel her anxiety and pain, you feel everything.

And I liked how Philip had enough of a plan to get himself out of hot water, at least temporarily.

That’s how deep these guys cover this stuff. He has a whole apartment set up that he’s never slept in once, just in case Martha asks. I love that writing.

Stan has a couple of big scenes in the episode too: His heart-to-heart with his son and then Sandra asking for a divorce. How was it wearing both hats for those scenes?

My only hesitation about acting and directing at the same time in some scenes was I didn’t get to give the other actors the full attention I thought they deserved. The advantage I had to remedy that was I’m on the show every week so I have a lot of time with the cast members before we shot the scenes to talk with them. It wasn’t confined to that day of shooting to have conversations about the work. I was able to get a lot of that done on our off time. And on the other hand, in a weird way it’s actually an advantage because no one sees a performance more clearly and more perceptively than the other actor you’re working with. We always know how we’re doing with each other. Being behind the monitor is great to see what the viewer is going to see, but you feel it in a whole different way when you’re in the scene with the other actor.

On a character level, what’s up with Stan’s distrust of Agent Aderholt?

Aderholt is clearly a very motivated and intelligent agent. He’s digging up the old case files from season one, essentially. Stan had an extraordinary relationship with Nina that I don’t think he wants anyone nosing around. I think it just hits a nerve, like “Why do you keep asking questions about Nina and the illegals?” He’s protective and defensive over some of his behaviors in the past. He respects Aderholt, but because of that respect he’s even more worried about him getting too involved in Stan’s previous experiences. And now with Stan and Oleg, Stan has gone completely rogue in a way to try to get Nina out. It’s not sanctioned, not official — a really smart nosy agent asking questions is not what you want in your life.

And then Aderholt finds the bug in Gaad’s office.

I think Stan’s certainly happy the bug was found but I’m sure he wishes he found it.

What was it like directing Matthew and Keri? They’re three seasons deep in what I’d consider two of the greatest performances on television. How much do you work with them as a director and how much do you just trust them to handle?

They obviously know their characters, they’re both such fantastic actors that if you just sit back and shoot them they’re gonna make you look good. But there are opportunities to have conversations about the scenes, maybe finding some colors or possibilities that aren’t overtly obvious on the page and just fleshing out what each character is experiencing in the moment. But essentially they make me look good.

Philip has two new aliases in this episode. What is the process of developing those?

For that, you involve wardrobe and makeup and hair and start to figure out what can we do here. “Who is this person? Let’s invent somebody that’s interesting and fresh and new.” It’s a group effort. Obviously it begins and ends with Matthew, but it is a collaborative effort. It’s such a challenge on the show to keep finding new characters they can play as undercover identities.

Do you weigh in on the hair? Philip has amazing new wigs for both identities.

Yeah, you do. For the scene in the diner, because I’d never seen them do this before, I said, “Wouldn’t it be cool if they were kind of punkish?” I threw it out there and everyone responded enthusiastically and did their thing. We ended up with those two characters. I love that couple. Keri too with her purple eyes and that blonde pixie cut. They look great. And it really fits the setting of that part of the story.

Keri Russell wigs out as Elizabeth Jennings on “The Americans.” Keri Russell wigs out as Elizabeth Jennings on “The Americans.”

Did you know during filming you’d use Fleetwood Mac’s “The Chain” for your big action climax?

You don’t really know until you’ve finished the final edit. You have your wishlist and then you find out if you can get the rights to it and if you can afford the rights to it. We had a couple of options. On top of the list was the song that’s there now. I was sort of dazzled we were able to get it. I thought it would be out of our reach. It’s a big buy, but everyone loved it. We have a great music supervisor, and we whittled it down to a couple of choices — the more expensive and the cheaper choices. Everyone loved it so much that we got to keep it, and I’m really happy that it’s there.

Do you rework the sequence at all once the music is set?

It’s amazing how malleable music and picture are. But once you decide on a final track you often go back and make little tweaks so it really lays in perfectly. You cut to music but you don’t want to box yourself into one track.

Were you disappointed there was no Nina in this episode?

I can’t complain, I had a great episode and got to work with so many of our cast, but it would’ve been great to work with Annet (Mahendru). Obviously we’ve worked a lot together before as actors and I was really hoping to get the chance to work with her as a director. You can’t have everything.