THERE’S nowhere more depressing than a prison in a zombie apocalypse.

Imagine blood splattered over sparse, claustrophobic cells and decaying prisoners lumbering around in dull grey pyjamas.

But it’s in this unlikely haven that sheriff ’s deputy Rick Grimes chooses to shelter his pregnant wife, Lori, their young son, Carl, and the rest of the motley crew that make up the cast of The Walking Dead.

As the Emmy award-winning show, based on the comic books, returns for a third series, its cast – led by Brit Andrew Lincoln as Rick – will still be filming in the countryside around Atlanta, Georgia.

Down the road from the studios where the prison set has been constructed in its entirety, in the idyllic town of Senoia, there’s a public notice to the residents that reads: “Stalwart Films thanks the people of Senoia for not mowing their grass.” You don’t mow the lawn in a zombie apocalypse.

Senoia is doubling for the fictional town of Woodbury, which has managed to barricade itself against the “walkers” under the direction of The Governor, a new character played by another Brit actor, David Morrissey.

The main storyline for this new series sees Rick and The Governor fighting for supremacy.

“It’s fair to say, if you know the comic books, they are not the best of friends,” says Lincoln. “I don’t want to spoil it, but suffice to say, it’s a clash of civilisations and ideologies.”

Also in the mix is Michonne, played by newcomer Danai Gurira, who was glimpsed at the end of series two. A fan favourite from the comic books, the samurai-sword wielding “warrior goddess” has two armless zombies in tow, that she uses as her pack horses.

“Imagine Serena Williams in an apocalypse – she ain’t going down easy and you’re going to want her on your team,”

says the 34-year-old, who was born in the US and grew up in Zimbabwe.

“Michonne recreates herself after the apocalypse hits. She figures she’s the higher life form, she’s smarter than them, so why live in fear and terror, when you can flip a switch and dominate the zombies?”

At the start of series three, Michonne is nursing Andrea, who got separated from the group when they had to flee Hershel’s zombie-infested farm. Somehow they’ve all survived the winter unscathed, but Rick has launched a “Ricktatorship”

and what he says goes – even breaking into a prison and taking down its zombie inhabitants.

“One of the things I loved about the comic book is that he turns up, sees the prison and says, ‘We’re home’ and we have a very similar line in the first episode. Rick views it as a saving grace, it could turn into a citadel, a potential safe haven,” says Lincoln.

The prison represents the possibility of new food, ammunition and weapons. The only problem is the zombies, so the battle doesn’t come without casualties.

And then there’s the new terror outside, The Governor, who’s described in the comic books as a maniacal tyrant.

“The human threat is massive, so it’s no longer just the zombie threat,” says Lincoln. “Every episode has ramped up and they’ve really tried to open out of the world of the show.”

Morrissey is annoyingly tight-lipped about his character’s clash with Rick, saying, “you’ll have to wait and see”.

But adds: “They’re both very strong leaders in different communities and it’s about whether they can live together in this world. Around them is this terrible, challenging landscape, so it’s about how they negotiate themselves through that.”

Morrissey found working in Georgia in the summer a challenge: “The elements are tough, but the people aren’t. The conditions are challenging, it’s hot, it’s muggy, it’s humid, but when you’re doing a show about an apocalyptic set of circumstances, the heat and bugs really add to that.”

For Lincoln, the best part about having Morrissey on set is simple: “I’m thrilled there’s a fellow Brit now having to do a twangy Southern accent – bring it on.”