Zombie drama The Walking Dead will be heading back to AMC for a fourth season, but without the guiding influence of Glen Mazzara, who has stepped down as showrunner.

In a joint statement, Mazzara and AMC noted: “Both parties acknowledge that there is a difference of opinion about where the show should go moving forward, and conclude that it is best to part ways.This decision is amicable and Glen will remain on for post-production on season 3B as showrunner and executive producer… AMC is grateful for his hard work. We are both proud of our shared success.”

Mazzara separately said: “My time as showrunner on The Walking Dead has been an amazing experience, but after I finish season 3, it’s time to move on.  I have told the stories I wanted to tell and connected with our fans on a level that I never imagined. It doesn’t get much better than that. Thank you to everyone who has been a part of this journey.”

Creator Robert Kirkman diplomatically said: “I am in full support of both AMC and Glen Mazzara in the decision they have come to and believe the parties came to this decision in the best interest of the future of the show. I thank Glen for his hard work and appreciate his many contributions to The Walking Dead and look forward to working with him as we complete post production on Season 3. I am also excited to begin work on another spectacular season of this show that I know means so much to so many people. This show has always been the result of a wide range of extremely talented men and women working tirelessly to produce their best work collectively. I believe the future is bright for The Walking Dead. Thank you to the fans for your continued support.”

Sons of Anarchy creator Kurt Sutter was rather less diplomatic in his comments: “AMC is run by small-minded, bottom-line thinkers who have no appreciation or gratitude for the effort of its creative personnel. Time and time again we see events like what happened today with Glen Mazzara. They continue to disrespect writers, shit on their audience and bury their network. Mazzara took the work-in-progress that was Walking Dead and turned it into a viable TV show with a future. Without him, that future is dim. Showrunners are not development executives, we’re not cookiecutter douchebags that you plug into a preexisting model. TWD will suffer. Even Zombies need consistency.”