Ahead of The Walking Dead's season 8 end Sunday, series stars and executive producer Scott Gimple are weighing in on the "unbelievable" and "surprising" finale that promises to bring closure.

Asked to describe the season closer, leading man Andrew Lincoln says he can "do it in three letters: WTF."

"It's unbelievable," the Rick Grimes actor tells The Hollywood Reporter.

The episode, "Wrath," basically acts as a series finale, bringing to a close storylines from the first 115 episodes and setting the stage for a new iteration of the show as it heads into season 9.

That means ending the ongoing conflict with Rick Grimes' camp and Negan's Saviors, who have served as the overarching threat for two-and-a-half seasons.

Comic book readers might be expecting the finale to hit certain beats, but Gimple says there are bigger surprises in store that even fans of the book might not see coming.

"If I said it mirrored [the comics] super closely, that would provide a lot of answers," Gimple says. "Aspects of the comics are there, and then there's some other stuff in there and some big left-hand turns to the comics."

Adding the finale is "totally the same, and no it's not at all the same and it's completely different," Gimple promises the last episode this season "will indeed" bring closure to the tease of a red-eyed and bloodied Rick Grimes laid up against a tree — flashes of a future event interspersed throughout season 8.

But this finale is even bigger than The Walking Dead's usual season conclusions, already typically the biggest episodes each new season: this finale "closes down every character's story pretty much in some tragic ways and in some sad ways, and even some hopeful ways to a degree," Gimple says.

"There's closure, in every iteration of what that means, in the finale."

What does that mean for Maggie Rhee's Lauren Cohan, who is the only cast member yet to re-sign a new contract for the upcoming season?

A contractual dispute with an actress with a fulfilled contract could signal a death warrant for a character on a zombie show, but when it comes to deaths in the finale, Gimple says only: "I shan't say one way or the other."

Asked if that closure means an end for the Hilltop leader, Gimple says the episode "doesn't really address that in any way."

"There is closure for Maggie, and it's a big part of her story," Gimple says, "but I shan't say anything about the meta of it just yet."

As for Pollyanna McIntosh, who plays Jadis, "the surprises do not stop coming," the actress says of episode 8x16. "There's always more to know. I think that's definitely true of this finale."

The episode also marks the exit of four-season showrunner Gimple, who will now oversee the entire Dead brand for AMC, including credit on spinoff Fear The Walking Dead, which brings Walking Dead veteran Morgan into the fold.

James, who was given a choice to depart The Walking Dead and head west for the spinoff, says the finale brings a "fantastic" end to this specific chapter of Morgan's story.

"The way we've handled the war, and all of the turns in the war that will lead to victory for one side or the other, is all handled really fantastically," James says.

"The surprise and the revelations that happen in the finale have all been well earned. It's a fantastic slow burn. The challenges that the battle between Negan and Rick have brought out in both men have been absolutely fantastic. The way the lines have been blurred between who is right and who is wrong has been spectacular storytelling. It all pays off in this final episode."

The series has already broken ground on season 9.

The Walking Dead airs its extended season 8 finale Sunday, April 15 at 9/8c on AMC, immediately followed by the Fear The Walking Dead season 4 premiere.