"This entire season was based on the premise of, 'Can you do what it takes to stay alive?' " the exec producer tells THR in our weekly postmortem.

[Warning: This story contains spoilers from episode 415, "Us," of AMC's The Walking Dead as well as the comic book series it is based on.]

With only one remaining episode left to go in its fourth season, AMC's The Walking Dead revealed the first look at the much-heralded sanctuary known as Terminus.

With Rick's (Andrew Lincoln) group divided since the fall of the prison in the midseason finale, two of the mini-groups were reunited and arrived at Terminus during Sunday's penultimate episode. It came after Abraham (Michael Cudlitz), Eugene (Josh McDermitt) and Rosita (Christian Serratos) connected with Maggie (Lauren Cohan), Bob (Lawrence Gilliard Jr.) and Sasha (Sonequa Martin-Green) to save Glenn (Steven Yeun) and Tara (Alanna Masterson) when they attempted to plow through a terrifying tunnel. Maggie and Glenn's reunion marked the latest glimmer of hope this season and came after last week's devastating episode in which Carol (Melissa McBride) had to serve as judge, jury and executioner and kill Lizzie after she murdered her kid sister, Mika.

Meanwhile, Daryl (Norman Reedus) learns the new rules of Joe's (Jeff Kober) group -- and that the latter wants revenge for the man who strangled one of his companions. What Daryl doesn't know is that Joe is referring to Rick, who killed the guy in order to save the lives of Michonne (Danai Gurira) and Carl (Chandler Riggs), and that trio is traveling just ahead of Joe and Daryl's group, as everyone is poised to arrive at Terminus in next week's season finale. (Read our recap and analysis here.)

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The Hollywood Reporter caught up with executive producer Greg Nicotero, who directed Sunday's episode, to break down what could await in Terminus, the rest of the community there and to preview the season finale.

The first of the group have arrived at Terminus. Mary (Denise Crosby) can't be the only one there, right? How would you describe the rest of the community?

No, she's not the only one who's there. She's the one that we see first, but we'll quite quickly meet others. In this particular situation, it's easy for them to get in. It's not like they had to go through checkpoints or anything. As they're walking into Terminus, the gate is open and there's a note that says to close it behind you. We see flowers, and we hear a bit of noise from some people milling about. Mary just happens to be the first one; she's the welcoming committee.

After seeing the lengths by which Rick's group went to protect the prison, why wasn't Terminus more guarded? It feels a little too good to be true.

If it's a group of people that have been posting signs all over the Georgia countryside and doing radio messages, they're trying to rebuild the world. I'm sure that they have had to deal with good people who showed up and probably people who wanted to rob them, who knows. But you have to start somewhere, and clearly we met the "Claimers" and that situation did not end well for Len (Marcus Hester). You see that there are people out there who have their own rules. What I love about what Joe (Jeff Kober) says, he says, "There are no rules out there anymore; you either kill or be killed, and you survive." They have found a way to survive. The fact that they're on their way to another colony and group of people that have learned to survive is pretty exciting.

We've been so segregated in the last couple years of the show: season two we were at Hershel's (Scott Wilson) farm; and season three and half of season four, we were at the prison. This is the first time we're out in the world experiencing it and seeing the vast devastation and destruction but also how people survive. Clearly the Claimers survive by throwing out the rules, and we're now getting a chance to learn about Terminus that has been able to survive and not be so creepy, weird and malevolent about it. Everyone gets to Terminus and smiles and thinks, "Maybe the world isn't all a bad place."

The Claimers have one set of rules; Rick's people have another, and now Terminus is an X-factor -- plus Abraham, who is very mission-oriented. How might all three groups get along? Could there be a three-way battle for Terminus?

It makes sense that Abraham's mission is his No. 1 sole purpose. We establish in episode 15 that he's willing to do anything to get Eugene there. This episode is the first time we get an opportunity to see the dynamic between Eugene, Rosita and Abraham. Abraham says, "I'm going to Washington. I'll probably get there more safely the more people I have with me." He's trying to enlist as many people as he can because the more people he enlists for the mission, the greater the likelihood that Eugene is going to get there safely. When and if they meet up with Rick and his group, would Rick be willing to go along on that mission, or will they find a place to hold up at Terminus that allows them the safety that they've had for the past three years? That's what we're going to find out.

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How might people respond to Eugene's claims that he has a cure for this epidemic?

There's a difference between knowing and having a cure. If you're in the middle of this devastating epidemic and someone says they know how to fix it, clearly the world is going to be a different place. It's not like you can flip a switch and everything will be fine. On our show, we get glimpses into what the day-to-day events do to people emotionally and physically. The last we saw Daryl, he had been chasing the car that grabbed Beth and he couldn't run anymore. He meets this group of guys and you feel like at any second, Daryl will say, "I'm done with you guys; this isn't a world that I want." But at that point, Daryl is numb. He's lost everything and everyone he's ever loved. His choice now is to live alone or join this group of guys who clearly have something going right, otherwise they wouldn't be around. We see a change in Daryl during this episode, where at the beginning he doesn't want to engage Joe in any conversation, and by the end, they're sharing a cigarette together and Daryl sees the strawberry bush and says, "Claimed." That speaks volumes because Daryl has found a new group and a new way to survive as well as a reason to survive. That's an intriguing plot twist because knowing where Daryl is and that Maggie and Glenn are back together and their mission is to stop at Terminus, see what it is, and then head off to D.C. -- they have a bigger army. It's one of the first times in a long time that we have a nice, happy moment when Glenn and Maggie reunite and have that beautiful scene in the tunnel where she burns the picture and says, "You're not going to need a picture of me ever again."

How might Daryl fare when he's pulled between his life in Rick's group and this new gang with Joe? He seems like he's regressed a bit to his old preapocalypse life here.

It's survival; that's what people do. Rick has shown us the exact same thing. Look at what Rick has become since the beginning of this season. In the first half, Rick stepped away from leadership and let the council deal with it while he focused on raising his children and providing for the group. When The Governor shows up in episode eight, Rick says he's not in charge and The Governor doesn't care. The Governor pushes him back into that place where he's the reluctant leader, and it all goes to hell. Rick has really been pushed to this place where he's had to make these decisions, and it's the same for Daryl. If Rick didn't make that decision to strangle that guy in the house, Michonne and Carl would have been killed. So he did what he had to do, and it's the same with Daryl. He could have sat on the ground and let a herd of walkers come through, but instead Joe came first. It would have been interesting to see if Daryl would have been surrounded by walkers vs. surrounded by those guys and what decision he would have made because at that point, he didn't give a shit.

Maggie and Glenn are reunited and both have never given up hope this season. Could we see a season finale more about hope than bloodshed?

We're going into it with hope. We've been hearing since episode four about Terminus and those that arrive, survive. They all have that glimmer of hope. The fact that Glenn says "Maggie would go there; I know it," and vice versa, they all find those landmarks and realize that in a world without cell phones, computers and cars, they have to have faith that they will find each other. Tyreese really lost his faith after Karen died, and reuniting with Carol and the girls, it's amazing and gut-wrenching to see what all these people have been through. As far as Tyreese knows, Sasha is dead and vice versa. Maggie doesn't know Beth is gone. It's all these little microcosm of stories that will all collide.

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Carol and Tyreese are not that far off from Terminus. How might they respond to a new group of people after what they've just been through with Lizzie?

We don't know what point people will arrive there; we know everyone is headed there. We know the Claimers saw the Terminus sign, and everyone is on the tracks and headed that way. But we don't know what configuration they'll be in and when everyone arrives. Everybody has their own rules of survival, and some that work for some people won't work for others. The whole "claimed" idea that you have to say that word and it's yours, whether you're there first or not doesn't matter. It's a unique perspective.

We still don't know where Beth is and who has taken her. Is it fair to expect we'll see her again in the finale?

I can't tell you that.

We've yet to meet Andrew J. West's character. What can you say about his arrival in the season finale?

We're at Terminus and we've seen some of our group arrive there, and it's safe to say that that's where we will find him.

What kind of a man is he? My theory is that he's a version of one of the cannibals from the comics.

That's an interesting theory. The people that have survived in this world have survived at a cost. The way Joe and his group, the way that our group have survived, they've lost people and they've had to do things. This entire season was based on the premise of, "Can you do what it takes to stay alive?" Crossing that line between the brutality and the humanizing aspect of life, and can you be compassionate and still survive in this world or are you always going to be a bad guy? In different worlds and different perceptions, who is a good guy and who is a bad guy? In Joe's perception, Joe isn't a bad guy, he's a good guy who has just figured out a way to survive and use a set of rules that work for him. So it'll be interesting to see how things play out and how fans respond to what we've set up in the last episode.

This episode was different than some of the penultimate episodes of previous seasons -- no major character deaths and it ended on a hopeful note. Are you setting us up for a deadly finale?

The second-to-last episode is always challenging because we're teeing up the finale. Last year was Merle's death, and the year before that was Shane's death, and the year before that was Amy's death. The second-to-last episode is always a challenge because we're putting our foot on the accelerator and getting the show ready to launch into the finale. We very rarely get light moments; the show is pretty heavy. So the reunion of Maggie and Glenn was really important to me, and those two did a fantastic job of taking us there.

What did you think of Sunday's episode? Do you trust that Terminus will be a safe place? Hit the comments below with your thoughts. The Walking Dead season finale airs Sunday at 9 p.m. Stay tuned to THR's The Live Feed for more coverage.

Email: Lesley.Goldberg@THR.com

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