As FX’s “The Strain” careens ever closer to a looming vampire epidemic, Corey Stoll’s Ephraim Goodweather remains the logical center at the eye of the storm — but that stoicism won’t last for long, according to the show’s star.

Variety sat down with Stoll at FX’s recent Television Critics Assn. summer press day to discuss Eph’s transition from brains to brawn, his experience working with Guillermo del Toro and the chances of maintaining a romantic relationship in the midst of a vampire apocalypse.

Considering everything is rapidly going to hell, Eph has done a remarkable job of keeping his cool and approaching the growing epidemic with a relatively level head, thus far. How long is that likely to continue?
Stoll: [Laughs.] Yeah, not very long. I mean, he is controlled within the context of all the shit that goes down. He does have a control over his emotions and it takes a lot for him to really lose it, but certainly, by the end of the season, he will.

He’s obviously got a lot going on professionally and personally, and we’ve seen him struggling with that balance, especially in the first couple of episodes. How is the show dealing with that balance between the professional and the personal, going forward?
Without spoiling too much, they’re very much intertwined, and I think it’s very important. Maybe in a movie we would be telling the story of New York being infested with vampires, and we’d show shots of millions of vampires, and we would be back in the situation room at the White House. But because it’s a TV show, and we’re telling the story over such a long [span], it really has to be domestic on a level, and it stays that way.

Obviously, it’s a vampire show, but the threat is initially portrayed as more of a disease or viral outbreak, which I think grounds it in a smart way. While it’s not something that could literally happen, a similar kind of contagion could happen, in terms of the rapid spread.
Having done some research on Ebola, and the Ebola-like diseases, there are things that Ebola does to the body and to the brain that are pretty vampiric, that you would not believe if you hadn’t read them in a nonfiction book. It really can cause complete psychosis and the extremes of what it could do to your body, the incredible temperature changes, and the liquefaction of organs, all this stuff, in an incredibly short amount of time. So, vampirism is more than just a step beyond that. Its several steps beyond that. But evolution has brought these microbes up to a certain place of being very far out of our every-day reality.

Do you think that’s what makes the show so scary, in that you have a crisis that’s not so far removed from reality because, conceivably, we can have similar kinds of infectious outbreaks that can decimate populations?
Yeah, I think it’s absolutely terrifying. That’s where the show starts, but it departs from there. That’s how we have an entry point into it. That’s a lot of what really intrigued me by the project to begin with; it starts off as this contagion sort of thing, and then it becomes a real monster show, and then it really becomes something even more mythological. It’s exciting that it’s a TV show that doesn’t have to be one thing and stay that way the whole time. We’re in a place in the evolution of TV where characters — and even the form of the show — can change over time. I think Walter White in “Breaking Bad” was the best example, maybe the first time really that a TV show really allowed their main character to be different. That’s a different course, but that is a course that Eph is on. Eph will not be anything like what he is now, 60 episodes from now.

Will we see him evolve into more of an action hero, for lack of a better description? We’ve seen that he’s capable of defending himself, but he obviously starts out from a much more scientific and cerebral place than as a physical threat.
Oh, yeah. I start swinging a sword, and shooting my gun. I mean, I don’t know how good I’ll be. [Laughs.] I didn’t get that good in season one, but probably better than is realistic. I don’t think I’d be that good a shot — even though I’ve shot guns in TV shows, I’ve never done it real life. But he’s not Blade.

Can you preview Eph’s journey in terms of his relationship with his son this season? You’d imagine that an event like this would crystallize everything that he’s struggling with in regards to fatherhood.
I think Eph is somebody who is taking on more responsibility than he has the ability to fulfill. He has… not a God complex, but he definitely feels like everybody in New York is his responsibility, and he’s sort of backed up into that. He wasn’t intending to be a bureaucrat in that sense. He was in love with the pure science of it, but his ambitions got away with him, and suddenly he found himself in this position of responsibility, and he can’t turn his back on that for a second. He also has a son who’s his responsibility, and so those two responsibilities are often in conflict, and through all of the 13 episodes that we shot, it’s a constant push and pull, and there are times when he has to neglect one or the other, and the reality is that Zach (Ben Hyland) is going to have to grow up really quick. There’s no way that Eph can shield him from all of the death and danger around him.

We haven’t seen much backstory between Eph and Nora (Mía Maestro) yet, but can you talk a little bit about why he’s so drawn to her, and what that connection is?
Despite Eph’s swagger, he’s not a player. That’s not how he operates, and he really is in love with Kelly (Natalie Brown). She’s the love of his life and the mother of his son, and it’s only after she breaks it off with him that he would even think of starting something with Nora — but he can’t commit to that. That is a definitely a workplace romance born of closeness, and comfort, and being comrades, and having so much in common, but I think Kelly was the one who taught him what it was to love, and so… unfortunately a vampire apocalypse is not the most romantic place to start a relationship, but it does get complicated.

Eph and Nora now know that Jim (Sean Astin) allowed the coffin out of the airport — and were less than pleased about it– so what can you preview about the dynamic between the three of them, going forward?
Circumstances force us to get to work together, and that’s the really important thing in the storytelling too… The show is about our relationships, and our conflicts, and Jim and Eph go back a long way; they’re really brothers, and so we’re forced into some very painful conflict.

Kevin Durand’s character was introduced in episode two, but he’s on a somewhat separate track from Eph’s at the moment. Can you preview anything about the inevitable meeting between your characters?
It takes a while. I think it’s episode eight that our characters first cross paths, and that relationship starts at its most contentious — we really are forced together under the worst circumstances. And the triumvirate of me, him, and Setrakian (David Bradley), and the way those relationships sort of bounce off each other, is really fun.

Describe the experience of working with Guillermo del Toro, since he came up with the concept and clearly has such passion for it.
It’s so cool. You can tell just from meeting him, or seeing an interview with him, he has such an infectious enthusiasm and such a quick intellect but also, he’s interested in very high brow and low brow [forms of art], and there’s really no difference in that for him. H’s a riot. He’s so funny. He’s somebody who is doing exactly what he wanted to do since he was 12, and that 12-year-old shows up every day. He’s got a number of decades of incredible skill and the ability of divvying up tasks, and everything you need to do to be an effective producer and director, but at the core, every decision is made with this instinctual appetite for fun.

The show certainly has its grounded elements, but it’s still a very heightened world. While you were filming, did you have any moments where you thought, “This could all go so wrong, what are we doing?” Or, because Guillermo and Carlton Cuse were involved, did that give you more of a buffer against the insanity of the situations your character was in?
On a day-to-day basis you’re sort of bouncing back and forth between the two. When you’re dodging a six-foot tongue that’s not there, and you’re in the basement of some abandoned hospital and it’s ten degrees below zero outside, there are moments where you’re like, “What am I doing?” But that’s why I choose to work with the best people in their fields, because the realities of shooting anything, if you start to become self-conscious, [you feel] ridiculous, and you just can’t fixate on that. It’s a big game of make believe, and it’s a big leap of faith, and the best way to protect yourself is to commit and to work with people who are great. I’ve really lucked out a lot in my career, so far, trying to follow those two ideas.

Your work in “House of Cards” seemed universally lauded among critics and it felt like there was great interest in what you would do next, as to whether you would land this kind of lead role and get to show off a different facet of your range. Did you feel any pressure from that attention, or are you just enjoying the ride too much?
I really feel like it gave me leeway, in that I showed that I can act, and that I’m not an idiot, and now I can do something where you take yourself a little bit less seriously. I think a lot of what actually goes wrong with “House of Cards” is [people] think it takes itself more seriously than it does. But this is another level of, sort of like kids playing, and I love that stuff. I remember reading the script and just thinking, “I want to do that. That looks like so much fun.” I think about somebody reading the script for “Star Wars,” and it would be so easy to say, “This is silly. I’m going to pass this up,” and really missing out on something new. I think this has a chance of being something new, which is pretty rare.

“The Strain” airs Sundays at 10 p.m. on FX.