What's Next For 'The Walking Dead': Michael Cudlitz, Disease & More

"The Walking Dead" Season 4 got off to a killer start on Sunday night (pun intended). But where will the AMC zombie drama go from here? Warning, spoilers ahead.

Look for theme of the season to be about retaining humanity. Executive producer and comic co-creator Robert Kirkman told EW that a the theme was set in motion by Rick's encounter with the woman in the woods. "It’s 'Aren’t these people too far gone?' And 'Can these people retain a little bit of humanity?' We’re going to be dealing with those questions a lot more intensely than we have thus far on the show. It’s all about Rick coming from this place where he kind of went off the deep end in Season 3. Rick feels like he failed at everything he was trying to do and so this is him trying a different path and seeing if he can make that work," he said.

Prior to the Season 4 premiere, the stars and producers of the show teased a brand new threat. It was revealed at the end of the first episode when Patrick succumbed to some kind of virus that presumably also wiped out one of the pigs.

"Pulling in a new threat in your fourth season, I think, is a good thing," Kirkman told Vulture of the virus. "Also, it’s important to know that this is really just some form of the Spanish Flu. It’s something that exists in our everyday world now; it’s a time where there is no modern medicine. Scott Gimple, the new showrunner, really wanted to explore that new possibility of the simple things, the really little things, coming to devastate these people. That’s what we’re going to explore."

Gimple said the zombie with the bleeding eyes likely died the same way as Patrick.

"In refugee situations, when people are in close contact like that, bad things health-wise have usually happened. In a third-world situation like this, the effects can be even worse. If that zombie died of the same thing that Patrick did, and Patrick said he was feeling ill, that would mean you'd want to stay away from those zombies as well. So standing up against the fence and smashing and stabbing them in the face, there's a great deal of blood flying everywhere. It's very bad news and presents potentially a very difficult situation beyond the simple difficulty of being around other people, which you have to be," Gimple told THR.

Later this year the Governor will re-appear and viewers will meet some fan-favorite comic book characters. "Southland" veteran Michael Cudlitz will play Abraham, Christian Serratos will play Rosita and Josh McDermitt will play Eugene.

Click over to THR, EW and Vulture for more.

"The Walking Dead" airs Sundays at 9 p.m. ET on AMC.

The Walking Dead