Production on the fourth season of the zombie apocalypse series \"The Walking Dead\" began this week in Atlanta, AMC announced. Based on the comic book series created and written by Robert Kirkman, the ratings hit is to return in October. It stars Andrew Lincoln as a former sheriff and single father trying to protect a group of survivors from the legions of the undead. It co-stars Norman Reedus, David Morrissey and Danai Gurira.