Showrunner Scott M. Gimple talks with THR about incorporating Negan's backstory and how the events of the deadly season seven will impact everyone.

[This story contains spoilers from "The First Day of the Rest of Your Life," the season seven finale of The Walking Dead.]

All-Out War has begun.

Sunday's season seven finale of AMC's The Walking Dead set the stage for one of the most action-packed sequences of Robert Kirkman's comic series as three communities finally came together to take on Negan (Jeffrey Dean Morgan) and his group of savage Saviors.

But the battle came at a price: Sonequa Martin-Green's Sasha sacrificed herself rather than allow Negan to use her to against Rick (Andrew Lincoln) and her friends. Instead, she turned into a walker and came thisclose to taking a bite out of Negan's surprised face.

Sasha's death capped a season that explored the importance of fighting for a life worth living and a world worth protecting as the biggest battle for Alexandria, the Hilltop and the Kingdom is ahead.

Below, showrunner Scott M. Gimple talks with The Hollywood Reporter about what to expect when season eight of the zombie drama returns in October.

Season seven was about standing up for humanity and democracy — and a life worth fighting to protect. Do you have the theme of season eight?

We do. I don't have the public theme (laughing). We've been talking to writers, producers and the network about the theme and asked to please not tell anyone because it reveals the story. There is a theme, but if I told you, you would know what the story is going to be.

Is there a sense of what this victory means for everybody and where they go from here? Obviously this is just the beginning of war.

The turn of the story is really going to dictate the structure of the story and the speed of the story. The things that they are getting into demand a more kinetic narrative. The pace is accelerated by virtue of the things that they're up to. Though I don't want to say exactly, anybody who watches the show can extrapolate that they're now into public conflict with the Saviors; the battle lines are drawn. There isn't quite as much time to dig into anything but prosecuting the war.

Season seven was spent getting to know these new characters and locations. Structurally, how will season eight compare? With the accelerated pace you mentioned, will there be more episodes with everyone in them like the finale?

Yes, there will be. It's just where the story is going to. That presents all sorts of narrative and production challenges. We've known we were going this way for a long while; in fact, doing season seven, I remember talking to [writer and exec producer] Angela Kang about the difference between the structure of seasons seven and eight before we started seven. There's aspects to talking about season nine like that. We try to reinvent the show every eight episodes and I believe the differences between season seven and eight are going to be quite pronounced just by virtue of the narrative.

Will All-Out War last all of season eight? Is that just a first-half story?

I would never say!

It's a 12-issue arc in the comics that's relatively light on plot but high on action. Is there part of that story that you're looking forward to expanding?

There's a lot of twists and turns in All-Out War, parts one and two, and aspects of March to War that we didn't completely use. On top of that, there's the expansions within the story of characters that aren't in the book and situations that totally come from the book but yet are very different in some circumstances. By virtue of what The Walking Dead is, there is more stuff than was even in the book and stuff from earlier books that we might be dipping into, too.

We got a taste of this in the finale, but how will Sasha's death help further galvanize these three communities?

There's a continuum of people doing things for people, sacrificing for people, becoming part of other people for the rest of their lives. This was the first battle of the war. Sasha was the hero of that battle. She is, in some ways, the rallying cry, the inspiration and the strength. The momentum with which she led the proceedings is going to exist for a while.

Are there any specific characters you're really looking forward to seeing in season eight who will be impacted most?

It's going to get pretty intense and emotional in different ways. I'd say Rick and the group are coming off a win and even with the loss of Sasha, she was such a huge part of that win — she wasn't a victim, she was a team captain in some ways — and that's a good way for them to start the season and a good place for them to be. This isn't a time of them wringing their hands; it's a time to descend into righteous battle, which is a serious thing. They're not glib about it, but there is something extremely freeing to these people to be involved in such a noble cause.

Will there be a time jump when season eight comes back? There was a small one in the finale.

I won't be specific about that, but there will be no mind-blowing temporal shifts. But there might be a bit of a jump, but I don't think it'll be "oh my god"-level.

The finale had a touching Glenn moment at the end with Maggie's voiceover. Was there any conversation about having Steven Yeun come back the way Abraham did? Or was that largely because this was a Sasha story?

There was a conversation with myself (laughs). But you just answered it. That is where I landed, this was more about Sasha than Maggie. Even the idea that Maggie pushes at the end, which is Glenn's idea of what people mean to each other and how nobody really dies if you are the cumulative result of all the people you know, but especially those who have touched you. It was really applying that idea that Glenn had and expressed to Enid twice that I was trying to apply oddly from Maggie to Sasha and not from Maggie to Glenn.

In a remix of the comics, Carl fires the first shot in the war. How did you settle on that?

We were moving fast and playing with a lot of different iterations. In the end, it had to do with who Carl was, his position — where he was in relation to everything. He had the view and the opportunity, and that's the guy he is.

It was interesting to me because this is a kid who grew up in this world and has learned from watching his father's wins and losses. And this character is the future of the show.

He was completely prepared for that moment; he wasn't itching to shoot somebody, but he saw the opportunity that he had. He literally saw it better than a lot of other people in that position. And also, the Heapsters underestimated him.

Eugene lied to Negan about how she died. Is this the beginning of him seeing the light?

Sasha really did leave him with some heavy stuff — that she hasn't given up on him. Their last exchange was quite meaningful. I think the reason Eugene lied is because there's a very frightening man standing in front of him with a bat. Is the goodness in Eugene dead forever? Was it ever there in the first place? These are questions that we're going to explore.

Rick was betrayed by the Heapsters. What's his takeaway from this experience?

It has to do with strength; the focus that they all achieved and the things he's agreed to endure. In episode 12, the things Rick and Michonne talked about — the losses that could come — and being at peace with them and knowing that it's worth it. What they're doing is worth it. That gives him a singleness of purpose that has given him what he believes they need. They all seem to be on the same page.

Negan's backstory in the Image+ preview magazine makes him a rather sympathetic. Have you thought about incorporating that?

I might have gotten an advance on "Here's Negan." But it makes him somewhat sympathetic. Absolutely, I have thought about incorporating that. I will say in one of the most recent issues of the book, with Rick and Negan's discussion in the house, which reflected "Here's Negan" a lot, absolutely. I will say, not full bore but pieces of it spread out a little bit more. Negan's backstory has been weaved into his comic tenure and we do want to introduce it a little earlier than it was in the comics. So yes, but we're building it up.

We never saw Maggie put Walker Sasha down. And we never saw Sasha storm the Saviors compound. Why?

I would love to. It's a function of how much we get to show on screen. We had a lot of longer episodes in the first half and I wanted tighter episodes in the second half. There have been whole scenes that I've pulled that I hated pulling that I possibly could have put in, but it would have made the show longer and it would have meant more acts. It was a question of trying to do tighter storytelling. In the case of Sasha storming the Sanctuary, from a storytelling point of view, it was also leaving a bit of mystery mostly for Rosita (Christian Serratos). She doesn't know what happened, and that's pretty rough for her. That was the reason for that. For Sasha [the walker], when Greg Nicotero [who directed the finale] and I talked about it, we decided that seeing Sasha's back for this would be more effective for us just because she's gone; that isn't Sasha. And we've already seen her as a walker. It was much more important to play that emotion as Jesus and Maggie. I didn't want to cut away from Tom Payne and Lauren Cohan. And Maggie stabbing Sasha, it wasn't about violence or anything like that; we've seen that. I love that the audience knew exactly what was going on, and I was just playing with Maggie and Jesus' emotion. These little decisions add up to the entirety of the whole thing and you hope the cumulative effect of all of them brings the audience to the emotional and mental perception place that you want them to be. It's all just magic, and you hope for that alchemy and take these little pieces and make gold. It was very difficult to know for sure because everybody is different. You do it for yourself first.