'The Walking Dead' Season 4 Trailer Released: Zombie Hordes Threaten Prison Gang / Premiere October 13 [TRAILER]

AMC treated us with a special The Walking Dead Season 4 trailer Friday, September 13. Yes the guys over at AMC are that clever.

In the trailer, hordes of zombies appear right outside of the prison fences, threatening to break the defense and invade Rick and the gang's camp. How they got there, and how they got there al together isn't explained in the trailer, but something tells me the Governor can't be too far behind on the fiasco.

The nearly four-minute trailer also shows some fresh new faces in Season 4, young and old. Tyreese seems to have a bigger role in the upcoming episodes, as he's show defending the gang in part of the trailer.

As the trailer reinforces, The Walking Dead isn't about the zombies. Series creator Robert Kirkman already confirmed the zombies won't be evolving or changing their behavior in any major way in Season 4. Instead the emphasis is on the characters and what it takes to maintain humanity while trying to survive something so traumatic.

Rick's role as a father to Carl and Judith will be a major storyline.

"He repurposes himself towards raising Carl and Judith and protecting them emotionally instead of physically," Kirkman told TVLine. "He's trying to make sure these kids don't lose their humanity. That's almost the central theme of the season."

Check out the latest sneak peak trailer of The Walking Dead Season 4, set to premiere on AMC October 13.