* THE WALKING DEAD. 9 p.m. Sunday, AMC.

FOR SOMEONE who spent the first 13 years of her life in Cherry Hill, N.J., Lauren Cohan has quite the British accent.

Not that you'll get to hear it in AMC's "The Walking Dead," which Cohan joins in Sunday's episode, playing Maggie, a Georgia farmer's daughter who encounters the show's band of survivors after their exodus from zombie-ridden Atlanta.

"She comes from a very Christian background. She hasn't been all that exposed to the zombies," Cohan explained in a phone interview last week, trying to keep things spoiler-free. "She's not really been exposed to the world outside the world she lives in."

Cohan, on the other hand, has been out and about, leaving New Jersey for her mother's native Britain in her early teens and returning to the U.S. (birthplace of both her father and stepfather) at age 22. (Grandmother Barbara Cohan, she said, lives in Center City Philadelphia and she has other family "in the tristate area.")

After recurring roles in both "Supernatural" and "The Vampire Diaries" on the CW, Cohan's no stranger to the devotion some feel to shows with occult or science-fiction elements.

"I wasn't that up to speed on zombies, per se. But I definitely understood and respected like how serious people are about them. And I think what's so exciting about 'The Walking Dead' is that it's not really about the zombies," Cohan said.

"I mean, it's going to satisfy people that want the gore, and the horror and the intensity of the zombie attacks, but what I like about this vs. the comics [the show is based on] is that it's not just about the darkness. It goes so very deeply into these characters and how living in this kind of world makes us human or makes us into less-than [human]," she said.

As for the enduring appeal of zombies, "the only thing I can liken it to is fantasy realism. When I read a book that takes something very extreme and treats it matter-of-factly, it's an exciting alternate reality."

Right now, Cohan's reality involves filming about 50 minutes outside Atlanta, "in a very, very small town. It's kind of an adjustment . . . You don't even realize you're a city kid until you don't live in one for six months. But I like the South a lot," and had coincidentally spent some time living with her grandparents in Columbus, Ga., as a child, she said.

And then there's the accent.

She's sharing the challenge with "The Walking Dead's" London-born star Andrew Lincoln ("his accent's a lot more English than mine") and has worked with a dialect coach in Los Angeles.

"It's been really good to have Andy there. Sometimes I'll be like, 'Andy, how does the 'O' sound go again?' " she said, adding that they try to stay in dialect while on set.

That way, "you never forget that you're playing. It's fun."