A ticking bomb filled with sarin gas, waiting to explode. Carrie Mathison, giving chase to a terrorist down a dark tunnel. Peter Quinn, desperately clinging to life. And a wounded Allison Carr, on the run somewhere in Berlin.

Last week’s episode of “Homeland” left more than a few open questions heading into Sunday’s season finale, which was directed by executive producer Lesli Linka Glatter. As one of TV’s top helmers, she’s often been handed the reins for the show’s most pivotal hours, and while it was difficult to pry details out of her, she promises the season-ender won’t disappoint.

The finale shoot, she says, took a bit longer than usual — 12 days vs. the usual 9 to 10 — as the production roamed all over the train station in Berlin, with one scene filmed back at the CIA. “It’s wonderful to be back home (in L.A.) after seven months,” she says. “It was an incredible adventure.”

Here, Glatter talks to Variety about filming this season in Berlin during the attacks in Paris, what’s in store for key characters, and offers a tease for the “potent” finale.

How would you describe the finale?

Complicated. Emotional. And ambiguous.

What can you reveal about what happens?

There are lot of moving parts. There’s a lot of story that’s still up in the air, and especially where Carrie ends up at the end. It’s very emotional and potent. And it leaves open a lot of room for next season as well. One of the things that always excites me is that we have these 12 hours to tell the novel of this story. And there’s a lot of story that falls into each of those hours. That’s exciting.

What did it mean to you to be handed the mantle of directing the finale?

It’s a big responsibility to do the best possible job with the material. It’s always exciting and terrifying and thrilling all at the same time. With that short a time to prep and shoot, you really have to know what your story is about. You have to be able to look at the scripts, know what the themes are, know what the subtext is. You really need to know what you need to focus on. That hopefully makes for powerful storytelling.

How do you feel about this season overall?

I’m very proud of this season. It’s a bit intense that so much of the story we created has been playing out in some form in real life. That’s been disconcerting on so many levels. I was in the middle of shooting the season finale when (the attacks on) Paris happened. We were shooting in the subway tunnel under the Reichstag.

How did it feel to film there after the Paris attacks?

It was very intense. Sometimes when you’re reading the news, it can feel very distant. This felt very up close and personal. We were in another European capital. I felt it personally, having lived in Paris for three years. It’s a city I love. Sadly, it could have been anywhere. And that’s very sobering.

What did Berlin offer you as a director?

As a director it’s hugely exciting and challenging. It’s unbelievable to not have to be creating another reality everywhere you put the camera. Berlin is such an interesting city. So much of it was bombed during the war, so you have this interesting juxtaposition between very old classic architecture and very new, which creates real visual vibrancy. It’s the art center of Europe now. It reminds me of New York in the ’80s. And then you have a city that was divided in half. So psychologically it is a complicated place. Having one season set in Afghanistan and Pakistan and now being set in Europe in the heart of a city that has the strictest privacy laws, that is our ally but has a sense of distrust there — it is an interesting starting point.

Homeland” has always been eerily prescient, but this season especially.

Every season we reinvent the wheel. We have a series of meetings — myself, the writers, Claire (Danes) and Mandy (Patinkin) — with an incredible variety of intelligence experts in Washington. And we get this amazing series of seminars on what’s going on the world. Obviously no one’s talking about what’s classified. (Showrunner) Alex Gansa starts off the conversation with what keeps you up at night, what’s your biggest nightmare. The things that became the key topics in this last session [when we met] last January were Putin, ISIS and all the issues around privacy and how’s that’s impacted security.

The show pointedly doesn’t take sides on that issue of privacy.

One of the things I love is how we show both sides of an issue. In episode 502, when Laura is picked up and questioned at the BND, Astrid and Laura present both sides of the argument about privacy — and they’re both right. It’s opposing points of view but completely accurate and true from their characters’ point of view. It’s the shades of the gray where “Homeland” lives. It’s not black and white. It would be great if it was, but it’s not. That’s what’s so powerful.

There is a scene I shot in the first episode where Quinn is talking to all the chiefs of security back at Langley and gives a rundown of what’s happening in Syria. I remember reading the script thinking, this is the clearest analysis of what’s going on that I’ve read. Which is insane. We’re a TV series! Crocker says, “Is our strategy working?” And Quinn says, “You tell me what our strategy is, and I’ll tell you if it’s working.”

Journalist Laura Sutton is pretty strident in her arguments. 

She has a very specific view how the world should operate and what is appropriate and it’s completely valid. Astrid has another view because she knows what the other side is. And they’re both correct. But Laura is a truth-teller. It’s a question of looking at Snowden. Is he a hero or a traitor? I know what I feel personally, but maybe he’s a bit of both. He’s more a hero than a traitor. I don’t want people spying on other people. But there are the complications of having to protect a country. It’s not self-evident.

“Homeland” also presents both sides of the debate over the attack itself, with Qasim questioning Aziz.

Exactly. One would think Aziz is doing this out of some religious fervor and that’s not the case at all. Whatever assumption you make, there’s another side to the story. Now in every major city there’s a disaffected community that has not been a part of the bigger society. Whatever that community is, whether it’s Muslim, if you’re not part of the bigger discussion, that’s a problem. Education is a huge part of it. That’s a very difficult situation. We’re looking at that worldwide. How do we have a language to discuss together and come up with solutions to live peacefully together? Can you have that with ISIS?

This season the villain was Allison, a CIA agent who’d been a traitor for years. How did she manage to get away with it for so long?

Miranda Otto has done an incredible job as the complicated situation of an agent who gets caught and has to go over to the other side. What does that create? How does someone deal with that? What is the price you pay? What is the pact you make with the devil to deal with that? The CIA did that with Javadi in season 3. You try to turn them so they can come over to your side and you can have their intel. It’s always amazing to do that research and see the other side of that. I also loved seeing that episode where you see Carrie and Allison 10 years younger. I loved seeing an American agent being trapped.

What can you reveal about Saul’s fate in the finale? He wasn’t in a good place when we left him last week.

He has an extraordinary scene in the finale. I can’t say anything more. But I feel like our cast is so extraordinary and fearless. Seeing Carrie start off with some kind of normalcy in her life for the first time and be back in the world that she thought she was finished with is very compelling. She has amazing skills at being able to see the big picture. But that’s not a world she wants to be in anymore. That’s a whole other set of complications.

Will Carrie return to the CIA?

It’ll be interesting to see where next season goes as far as that goes. Until we have that series of meetings, I don’t know yet if Alex has any idea. But those meetings in Washington have such a big impact.

Any chance for a miracle cure for Quinn?

What incredible work has Rupert (Friend) done this season! He’s just extraordinary. I feel so lucky as a director to be working with this cast. It certainly has made me more fearless for sure.

Last season’s finale had a somber, quiet tone. How would you say this season compares?

It’s a different finale. It’s definitely not last year’s finale. Without giving anything away, this has a different rhythm to it.