The zombie drama's leading man talks exclusively with THR about the "seismic" change from the comics as well as his own future with the AMC hit.

[Warning: This story contains major spoilers from episode 808, "How It's Gotta Be," of AMC's The Walking Dead as well as the comic book series on which the show is based.]

The Walking Dead leading man Andrew Lincoln wants viewers of the AMC zombie drama to know that he was just as surprised by the events of Sunday's season-eight midseason finale as they are.

Yes, it's true: Co-star Chandler Riggs — who has played Lincoln's onscreen son for more than 100 episodes — is being written out of the series as Carl revealed to his father, Rick, in the closing moments of the episode that he had been bitten on the ribs. Riggs, who received news in June that The Walking Dead showrunner Scott M. Gimple was killing Carl off, will return in the Feb. 25 midseason premiere when Carl will die from the walker bite.

"It's huge," Lincoln tells The Hollywood Reporter in an exclusive interview. "I always thought Carl was going to be the one who led the show forward; that Rick would hand over his boots and revolver when he walked off into the sunset in season 28."

With The Walking Dead — which remains the biggest hit on television — not formally renewed for season nine and Lincoln's own contract up after season eight, the actor talks with THR about his own future with the series as well as how Carl's impending death completely changes the game. Click here to read THR's exclusive interview with Riggs.

What was your first reaction when you heard that Chandler was leaving?

My first reaction was silence. Scott Gimple called me up and said, "You're going to hate this one." He's very good about alerting the cast when there's going to be a [character] death. I tried guessing four times and was nowhere near Chandler Riggs' name. Scott had to say that it was Carl. I just didn't speak for a minute. I always thought Carl was going to be the one who led the show forward; that Rick would hand over his boots and revolver when he walked off into the sunset in season 28.

It's such a shocking departure from the comics and for the show as a whole.

It's huge. When it all happened, it was very difficult because it's such a departure from the comics and such a shock for all of us. Chandler was on set the day after and I went to see him and we had a chat. Everybody was reeling; I never saw it coming. But that's the point.

How does this fundamentally alter the fabric of the show?

It's one hell of a back-eight [episodes of the season]. It was incredibly sad, as you can imagine. It was challenging for me as an actor, but in a good and exciting way. I was nervous coming to work to try and factor in this radical change in Rick's life. I was trying to make sense of that as the show continues. This is seismic. As the season progresses, all of us kept saying that this was bigger than Glenn's death. This is the biggest death [of a character] we've ever had and probably ever will have, actually, if you are a comic reader and realize the importance of Carl in the comics.

Rick has now lost the last trace to his pre-apocalypse life after his wife, Lori (Sarah Wayne Callies), died during season three. How might he respond to this, especially as Carl was morally opposed to Rick killing all the Saviors in favor of having hope for humanity?

All of those questions are resolved in the back end of the season. The beginning [of the midseason premiere] is the most painful episode I've been involved in.

In terms of timelines, is it now clear that the teary/red-eyed Rick in the premiere was his response to losing his son?

All of that will be resolved in the back eight.

The same with what viewers thought was a "flash-forward" from the season premiere that included "old man Rick?"

Some of that will be resolved in the midseason premiere. The answers will come very quickly for some of the various futures that have been offered.

Is there a world in which that vision of considerably older Rick — which features Carl — that we see in the premiere is a vision Rick may see on his own deathbed? Is Rick safe in this world right now?

I wish I could say. Rest assured, these answers will come in the midseason premiere.

Your contract is up this season. The show has yet to be renewed for season nine, despite being the biggest hit on television. Do you see an end in sight for your time in The Walking Dead universe.

Yeah, I think so. I've said to you before and I really feel that the fans — and also for my own satisfaction — that there deserves to be an end point. There needs to be an end game and that is something that is definitely being talked about. (Laughs.) I can't get into all of that. But all of that will be answered. As I've said to you before — and I will continue to say — my relationship with Rick Grimes is far from over.

Do you see an end to Rick's journey coming sooner, rather than later — especially given Carl's impending death?

That's a question I'm not at liberty to answer. It's such an extraordinary story and in my heart, it deserves some resolution.

Carl's death propels this story in a direction that even longtime readers of the comics have zero idea about. That's a big change from these often season-long big-bad types, like The Governor and now Negan.

You hit the nail on the head. What happened in this season is exactly what we felt. This is a story about a war and this thing [Carl's death] happens that none of us saw coming that rapidly changes everything and moves us into a completely different universe and space. Of course, we're adjusting to the fact that it will be difficult [without Chandler and the Carl character] but it made a lot of the back-eight episodes a very dangerous show again. And that reminded me of seasons one through four because of what the boy represents to Rick. It's a big thing to lose one of the major agents that runs this man who wakes up in the apocalypse and has to find his family. It's huge. It's more than half of him. It is the future and it's been taken and that changes everything.

Will you be back for season nine?

I hope so! We'll see how this back eight plays out. The Walking Dead has been an extraordinary journey that isn't finished yet. I've always wanted to work in America because the language of American film is what I grew up watching and aspired toward. This job, I always wanted to raise my profile in America and this is beyond my wildest dreams. America is my second home now. I believe in America and in making stories in America. It's to be continued, is what I'd say in all areas. This one certainly feels like — when Glenn was killed, it felt like buttons had been pressed — and I certainly feel like this is the second button that has been pressed.

Lennie James is moving over to Fear the Walking Dead. Could you ever imagine yourself making a similar move to the spinoff?

It strikes me that they bagged one of the best leading men in Hollywood to lead the show; it'd be degrading to have another leading man. They're more than happy with Lennie because he's the best in the business.

With Carl's impending death, Rick is having to pay a huge price for taking Negan on.

That's woven into all of the back-eight episodes. This is the most tragic event that I could ever imagine happening, but it happened. And what it does is it focuses the back-eight episodes in a way that I never imagined. It's incredible and emotional and it gives it a burning white heat behind all of the action as we move toward a really remarkable season finale. It was a very challenging back eight, which was great for me. I have to be kept honest in the back eight as an actor; it wasn't a walk in the park by any stretch. I have to commend Chandler Riggs because his journey on the show is completed in season eight and the work that he did in these two episodes [Sunday's episode and the upcoming midseason premiere] is magnificent in terms of the way Carl went out. These are the finest episodes he's ever done in the eight seasons he's been on the show.

Can you tease the season finale in three words?

I can do it in three letters: WTF. It's unbelievable.

Stay tuned to THR.com/WalkingDead for more coverage from Sunday's shocking episode, including an interview with showrunner Scott M. Gimple, which is coming Monday.