[Warning: This story contains spoilers from episode 105, "Cobalt," of AMC's Fear the Walking Dead.]

AMC's Fear the Walking Dead dropped a bomb Sunday when Liza (Elizabeth Rodriguez) learns that — like on the flagship series — everyone is infected. Season one's penultimate episode also dealt the group its first major fatality when Griselda (Patricia Reyes Spindola) fails to survive having her foot amputated and Liza has to put her down.

Daniel (Ruben Blades), unaware that his wife has died, tortures a National Guard solider in a bid to find out where Griselda has been taken. Instead, he learns that the Guard locked up a group of 2,000 because they were unable to tell which people were infected and which weren't.

The hour also drove a deeper wedge between Madison and Travis, the latter of whom turned to the Guard with a plea to return the community's 12 people taken for treatment in a bid to safeguard the healthy. Travis is given the opportunity to put down a walker and continues to refuse. When he returns home to Madison, he learns that she allowed Daniel to torture a soldier.

Elsewhere, viewers meet Colman Domingo's Victor Strand inside the holding pen, with the wealthy "fixer" taking an interest in Nick (Frank Dillane).

Here, showrunner Dave Erickson talks with THR about the why of it all and previews what to expect from the drama's freshman season finale.

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The episode ends with Daniel approaching the auditorium that Adam, the Guardsman he's tortured, mentioned. Is he really going to try to open that door?

There is a larger plan that will hinge on what Daniel does when he discovers it. He's confirming Adam's story and has found the arena that he spoke of. He knows that there are 2,000 people there, so it's the idea that there are that many walkers behind those doors and now Daniel knows about it. We'll see what comes next. Daniel is quicker to accept the idea of what's behind those doors — it's not that they're zombies, it's that they're a threat. And for him, anything that's a threat, there is an efficient way to deal with that. One of the things we've come to realize over the course of this episode is that every story Daniel has told his daughter and about their past, it's all true — he's just swapped the roles. Rather than being a person who was persecuted during the war in El Salvador, he was a persecutor. We realize that this complicated man is now being revealed to be someone who was something of a monster in his own right back in the day, and now his daughter has to deal with that realization

What kind of conflict is that going to create between Daniel and Ofelia?

She grew up thinking that her parents were somewhat backward, Griselda doesn't know any English and they didn't assimilate. Ofelia has always thought of herself as the protector of her parents, and what she realizes is that there's a whole other side to who her parents were and it's going to be challenging for her. There's too much going on for her to take apart the false history in the finale, but going into the next season, she's going to have to relearn who her father is and come to terms with it — and see if she can accept him. The irony is that in season two she's in a situation where she wishes her father were the kind and benevolent person she thought he was, and she'll realize that as she continues to face the new world, that person she thought Daniel was is not helpful to our group. I'm always interested in the idea of false fathers and surrogate siblings. The father-son, father-daughter, mother-son dynamics and this larger, blended family — there will be a lot of identity shifts over the course of the show.

We learn that "Cobalt" is code for the National Guard to evacuate the L.A. basin. Is the order really to give up on civilization?

No, it's a tactical retreat, and there's a reference we'll hear later. They're retreating to a place we'll discuss in the finale. The idea is that this groundswell of the turn grows exponentially and it's trying as best we can to imagine what happens in Atlanta and in the comic originally and figuring out the steps that took place between Rick's (Andrew Lincoln) accident and him coming out of his coma [on The Walking Dead]. Going into season two, we still have to play with it because we're not quite at that point yet. We're not going to end the season exactly at the moment where Rick came to and went out to explore and find Lori (Sarah Wayne Callies) and Carl (Chandler Riggs). There are still things for our characters to discover. We have a better understanding of what the walkers are and that they're dead and not coming back. That's still something that Travis wrestles with. But he's going to have his come-to-Jesus moment fairly soon. Season two allows our characters to still wander and assume that there's got to be a safe haven — there has to be a city or a state that hasn't fallen. What we don't have yet is the benefit of [The Walking Dead season one] CDC episodes. We're not going to have one person categorically say to us, "Guess what: The world is gone." It creates this strange conflict between hope and despair because if you think there might be a place where everything is OK, it motivates you to keep going — but at the same time, when you're confronted with devastation, it gets depressing. That will be something we tap into next season.

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Speaking of hope, how is Liza going to respond to the awareness that everyone is infected?

She goes into the hospital because she feels responsible for Griselda and for Nick, but also because it's an opportunity for her to help, learn and function as a nurse — and then she gets broadsided with the realization that whatever this thing is, it's collective and we all have it. And when somebody does have it, they have no choice but to put them down. It's a heartbreaking scene when she has to put Griselda down. There are two things going on: she's failed her patient —this woman that she cares about — and she's getting this massive download about the fact that whatever this contagion is, it's something that has spread completely. That is information she now has and, in many respects, she is getting ahead of it in the same way as Rick at the end of season one. We'll see what she does with that information.

How might Daniel respond to news that everyone is infected — and his wife didn't make it?

Daniel will be able to adapt to this new world because he's a survivor — and always had been; whether he was the torturer or not, he's led a much harder life than most of our characters … with the exception of Nick, who has been on the streets for the better part of the last six years. The one person who's best equipped to handle this is Daniel — even when he realizes that Griselda is gone. He still has a family to take care of, so he's going to have to persevere. He definitely wants to find and save her, but he also is very pragmatic in his approach to the world. He has seen the worst about the National Guard from the beginning; he is the one that has seen what happens when the soldiers come and take people away in the trucks. He's going to be rocked by Griselda's death but he will persevere because he still has Ofelia and now that she knows what he is — or what he was — he needs to atone for that. That will be his drive going through the finale and into season two.

Who is this "closer" guy and what is his role inside the hospital camp?

Colman Domingo plays Victor Strand, and we'll find out that he was at the wrong place at the wrong time. Strand is a fixer but he's also a man of means, he's quite wealthy and gets scooped up when things go to hell. There's an irony to him being stuck where someone of his means would never be. He's a survivor in his own right. If you take Daniel and Strand and see how they interact, it's going to be quite compelling. Strand is a guy who recognizes that there's a shift in currency. He knows things are not going to get better for some time and that the shiny objects are not what matter anymore. That's why he's willing to give away his watch to the guard. We wanted to introduce a wealthier character that you don't see that often on the original show and see how they interact with our blue-collar family. He will be very important in how the season ends and where we go in season two.

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Does Travis still believe things will get better now that he's seen the outside world — and that the military is giving up? Even told that the walkers are no longer human, he still can't put one down.

Travis is going to cling to his hope and his humanity as long as humanly possible. If you had to pick one thing that this episode is about, it's very much a Madison-Travis divergence and following different paths to get their people back. Travis does the practical thing and goes to Moyers (Jamie McShane), whom he doesn't trust anymore. He's playing Mr. Mayor and trying to go about it the right way. Madison realizes what Daniel is doing and makes a distinct choice — knowing that he's torturing this poor soldier. She knows Daniel is going to do what needs to be done to get the information and she's going to allow that to happen. It's a distinction in Madison and Travis' relationship that's important going into the finale.

None of our characters have seen The Walking Dead. Would they have seen zombie films? I'm sure that they did. We're maybe 12 days into the apocalypse and one of the reasons the show was structured the way it was, was to put Travis in a position where he's got his finger on a trigger and a walker in his sights and he's got Moyers and the soldiers emphasizing that they're not people anymore. "And if you think it's a person, then we're killers." It's important that only 12 days into the apocalypse that there are people who still don't believe that this is the end of the world. That's really what we were trying to dramatize in this episode. And that's why, after going through that horrible experience when Travis finally makes it back home, he sees Ofelia and realizes what Daniel did and the true horror for him is this realization that the woman he loves [Madison] knew that Daniel was torturing this poor kid and did nothing. That completely knocks him off of his feet. Travis will have many surprises to come.

Is this the last that we'll see of the National Guard?

Not necessarily. We set up the idea that they're withdrawing from the L.A. basin, that they're going to retreat. We will get into what their destination is when we get into the finale. This will probably not be the last time we see the National Guard, at large.

How deadly will the season finale be?

It will be the deadliest episode of the season. There's a ticking clock. Travis, Madison, Daniel, Alicia and Chris are going to find out that their community isn't safe anymore. They're not going to have the protection that they thought they thought they would [with the National Guard], and they still don't have their family back [with Nick, Liza and Griselda, the latter of whom they think is still alive]. Travis' efforts to save Nick, Griselda and Liza didn't work, and we don't really get to comment on it. What Daniel did worked and now he has information and pieces that are going to enable the group to hopefully take some action going into the finale and try to save their people — and themselves.

Fear the Walking Dead airs Sundays on AMC. What do you think will happen in the finale? Sound off below.