I took up boxing to get in shape for filming because it's grueling - all the running, the heat, the yelling, the crying that we do.

Yeah, it's scary. During filming, it wasn't just jitters from being the newer guy there or the greenest guy there. It was also fear of not messing up such an important character.

I'm Korean-American. Not Colombian. My parents are first-generation, and I'm like... in-between, because I moved over here when I was four or five.

It was so ridiculous. We were just sitting there, thinking about how ridiculous it was because we literally had stray hairs on us. The camera couldn't pick up all the details, but we had some crazy things. We had huge slabs of fat on us and bits of nails and hair. It was disgusting. But, there's also the beautiful parts of it.

The biggest challenges are in the same vein. It's about retaining all that stuff. Also, the physical stuff is not as easy as we originally thought. I play a lot of sports and I remember saying, "Oh, I'll be fine, running around or doing anything."

The book is about zombies, in that it is the over-arching theme, but what's going on is the story of these people and how these survivors deal. I think that's so much more of an interesting story, and that's what really gets and hooks these readers into the book and the show. It's a mix of fans of drama, fans of AMC, fans of horror and fans of Frank [Darabont]. It's a lot of people just coming together and realizing a genre doesn't have to be fixed in one specific detail.

I remember the first day I got there, they started the take and after four takes I was on the ground, on my back, with a banana and a Twizzler in my hand, and my face was green, and they said, "You can't get back on set for another 30 minutes." That was a, "Welcome to Atlanta," and that put everything in perspective.