'The Walking Dead': Gale Anne Hurd on why the virus is Season 4's villain

the-walking-dead-season-4-virus.jpg

After facing a villain as blatantly evil as the Governor, "The Walking Dead" is making a big change of pace in Season 4. Only two episodes into this new season, it's clear that a fast-moving virus is the biggest and most dangerous threat the survivors at the Prison have to face -- at least until the Governor rears his head again.

The scope of the threat the virus poses became clear in episode 2, "Infected." Anyone could be infected with the disease that was able to kill Patrick in less than a day, and since it's unclear who already caught the bug, people's worst selves have come forward to defend themselves. Executive producer Gale Anne Hurd says the virus and all of its consequences were concepts the folks behind "The Walking Dead" were eager to explore.

"That's something that we hadn't examined before and I'm not sure if other sort of zombie subgenre have," she tells Zap2it. "It's something that we felt we needed to introduce at some point."

According to Hurd, the idea to incorporate the virus into Season 4 came at some point during Season 3, and it was something "The Walking Dead" comic book author Robert Kirkman had a hand in.

"It was very much a discussion that Scott Gimple and Robert Kirkman had had after Scott was announced as the new showrunner and as we had begun to develop how we would put our cast in jeopardy in a way that would be fresh and different, but also very much a part of the universe that we created," she explains.

But humans weren't the only ones getting killed left and right in "Infected." Rick Grmes had to sacrifice his pigs to protect the Prison, which is likely something Andrew Lincoln was very upset about. Hurd made it clear that even though the pig scenes were hard to watch, all the animals were treated well on set.

"We always have people from the American Humane Association on set when we're working with animals, and we're happy to have them. We want to make sure that we use best practices," she says. "We welcome it, because we want to do the right thing."

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

Photo/Video credit: AMC