The highly anticipated season 4 premiere of The Walking Dead airs tonight, Sunday, October 13 at 9PM on AMC. When we last saw our band of survivors they let into the prison the straggling strangers from the defeated Woodbury. Trailers tease a mysterious danger from within that’s “not really walkers and it’s not other people.” Whatever it is, will it drive Rick and company out of their safe haven as alluded to in the prison break-out poster pictured above?

The premiere is called “30 Days Without An Accident” and its written by new showrunner Scott M. Gimple and directed by special effects specialist and executive producer Greg Nicotero. Following the episode is the return of Chris Hardwick’s after-show Talking Dead with special guests Gimple and Castle‘s Nathan Fillion.

Update (10/14): Another Walking Dead premiere, another series high ratings record. 16.1 million viewers tuned into the season 4 premiere last night; 10.4 million of them fall into the coveted adults aged 18-49 demographic. TWD reigns as the #1 show on TV in that demo. AMC proposes that after factoring in time-shifted playback (DVR, etc.), last night’s premiere should exceed 20 million viewers. The previously most-watched episode was the season 3 finale which attracted 12.4 million viewers, 8.1 million of which fell into the 18-49 demo. In other words, the Dead continue to rise…exponentially. Talking Dead also saw big gains; it too debuted to its biggest numbers with 5.1 million viewers, including 3.3 million in the 18-49 demo.

AMC President Charlie Collier commented on the expected yet still exciting news, as he does. “Sincere thanks to the fans, who have welcomed The Walking Dead back for its fourth season with the highest-rated episode in the show’s history. We could not be more proud of this show and everyone on both sides of the camera who work so hard to give life to this story of character, leadership and survival. It starts with series creator, writer and executive producer Robert Kirkman, show runner and executive producer Scott Gimple and the director of last night’s episode (and the man behind the make-up) executive producer Greg Nicotero, their fellow executive producers and an extraordinary cast and crew who are giving their all every day. So clearly, thanks to them, the dead have never been more alive.”

Update 2: The Walking Dead season 4 premiere is now being hailed as “the most watched non-sports telecast in cable history” after factoring in Live+3 data; an additional 4.1 million viewers watched the episode in the three days following the live Sunday airdate bringing its total viewership to a whopping 20.2 million.