‘Walking Dead’ trudges on

(CNN) -- When we left "The Walking Dead" crew in the midseason finale in December, the original survivors were coming head-to-head with the Governor and his followers in the isolated community of Woodbury.

Gunbattles ensued, as did dramatic rescue attempts that led to a cliffhanger involving two of the show's central characters -- brothers Daryl and Merle Dixon -- in a ring, surrounded by an angry mob calling for their heads. Will Rick Grimes and the original survivors integrate into Woodbury? Or will human-on-human violence prove to be more dangerous than the roaming flesh-eaters?

AMC's popular zombie series resumes on Sunday, and CNN spoke with Robert Kirkman, executive producer and creator of the original comic book series, about what fans can expect for the last half of season 3, life after outgoing showrunner Glen Mazzara and how long even the undead can survive the apocalypse on TV.

CNN: "The Walking Dead's" ratings have exploded this season. What's connecting with audiences?

Robert Kirkman: AMC has a really great program with building viewership. They do a tremendous amount of work, running marathons, promoting those marathons, promoting the DVDs and working with partners like Netflix and iTunes to make sure everything is available. So while people are hearing news about the show, AMC is doing a really good job at helping develop the audience. Also, we're awesome. People seem to like the show.

CNN: Was there concern in the beginning that the adaptation might not be able to transition from the comic world to a broader audience?

Kirkman: I'm somewhat of a pessimist. I never expected this to get made; I never expected the pilot to get picked up; I never expected the episodes to make it to air. I didn't really treat this show like it was happening until it premiered and until the ratings came in. There was a good 24-hour period where I was thinking, "this is not going to last." I think that's relative to its success. There's really nothing like this on television. There's really no comparison. I never thought it would succeed or succeed as well it has. It's all been pretty surprising. AMC took this risk and put something really unique on television, and people are responding to it on the level where it's having other networks try to think outside the box. As a television fan, when I see things like "American Horror Story," these kind of crazy shows that you wouldn't expect to see on television, things like "The Following" -- it's really exciting to see all this new stuff coming in.

CNN: Obviously, the story and the art in the comic books stand out. Is the aesthetic of the show taking a certain direction that you're noticing?

Kirkman: Not necessarily. We try to focus on the struggle of human survival. That's really what's at the core of this show: the appeal of watching people persevere and endure and succeed. This show is very much about trying to rebuild civilization in a micro sort of way. It's about keeping a family together and keeping your loved ones safe. It's much more about that heart and emotion than the more splashy stuff you see with the zombies, the action and the horror.

CNN: The hook is "you get to see zombies eat people. Who doesn't love that?" But there's the mental anguish that the viewers are put through.

Kirkman: Yeah, the zombies eat people, and that's cool and everything, but you really care about those people that are getting eaten. You feel for the other characters when they run around, and you hope that the rest of the characters don't get eaten. That's a very important component.

CNN: As executive producer and a writer, how much input do you have on each episode that we see?

Kirkman: Well, I mean, I'm one of the writers in the writers' room. There's a piece of every writer in every episode, little suggestions here and there. Things that make it into the final episode that we sort of throw out on the fly in the writers' room. I, like all the writers, have tremendous influence in terms of what goes into the show. I go on set as a producer, I oversee visual effects with a lot of the other producers; I'm giving notes on edits and cuts. I work hand-in-hand with all the other executive producers and Glen Mazzara in season 3 and craft the show into what it is.

CNN: Speaking of Glen, it was recently announced that he'd be leaving at the end of season 3 for "creative differences." Where do you see the creative direction of the show going?

Kirkman: I think the creative couldn't be at a better place. I think we have a really strong season 3. Moving forward, it's important to note that television is a collaborative medium, and there may be an element that changes from season to season, but the core group, the core people that make "The Walking Dead" what it is, changes a little bit from season to season. The majority of people remain, so the show is still going to have the same flavor. I couldn't be more excited about all the things we're going to be doing in season 4.

CNN: Let's talk about the rest of season 3. What can viewers expect? What are some of the issues and themes that manifest?

Kirkman: I think we have some really cool stuff ahead. If you've seen the first half of the season, you know the people in Woodbury are there. They're led by the Governor, and they're definitely going to be a problem. You got Rick with his people, and they're trying to survive, and you have these two groups who are on this collision course. It's going to be coming to a head. You're going to see big conflicts and pretty huge stakes, and some pretty dangerous things are going to happen to these people. Some of them may not survive. As fast-paced and explosive as the first half of the season has been, we're really going to be upping the ante and escalating things where we reach a finale, where some pretty crazy stuff is going to go down.

CNN: Who do you think is the most compelling character at the moment?

Kirkman: It's really hard to pick. I could gush about every single character. The work that Chandler (Riggs) is doing on Carl is amazing. I think all the actors would agree: Watching his transformation over the first three seasons of this show is a really cool piece of this show. He's been expanding his role in very cool ways, becoming this child soldier that we've gotten to know. He's a character that I would recommend people pay attention to and watch. It's watching these characters grow and change over time. That's really the core aspect, and you don't really see that in a lot of television shows. When you look at season 3, sure, Glenn's there, Rick's there, Daryl Dixon's there -- but they're vastly different than they were in season 1.

CNN: With a show that's become so engaged with its fans, do you pay attention to reactions, either positive or negative?

Kirkman: I've gotten the benefit of working in the comic industry for 10 years. I've always been very tuned in to fan reactions, message boards and all that kind of stuff. I'm pretty good at ignoring the negative comments and not letting them get me too much. There's always going to be negative comments. Honestly, I've learned if you don't have negativity in fan reactions, you're just not reaching enough fans. With "The Walking Dead" being as popular as it is, I actually enjoy the negative comments. We're reaching people to a point where they care so much, they voice their opinions.

CNN: You've written two novels about "The Walking Dead." Have you had talks about turning those into films?

Kirkman: There's always stuff like that thrown out, but there's no plans like that right now. It's enough for "The Walking Dead" to be a television show, a comic, a video game, another video game and another video game. There's quite a lot going on in "The Walking Dead" world. I can't say there's never going to be a movie; it's just not on our radar yet.

CNN: In a perfect world, how many seasons do you see this show lasting?

Kirkman: I think we'd be incredibly fortunate if we were one of those shows that got to go seven seasons. I think that's a good possibility in our future, the way things are going. Hopefully, we'll make it there. At the same time, this is a very unique show. You never know. Personally, if I could wave a magic wand, I'd make it go 20 seasons. This is the kind of story that is exciting to watch these characters grown and change over time. The comic book has been going for a decade and probably will go for another decade, I hope. I have no intention of ending that any time soon. I think there will always be a wealth of story potential in a universe like this.