What are Xombies? That's a good question, and I'll answer it by briefly explaining what I was shooting for when I started writing the original Xombies back in 2001.

I was strongly influenced by George Romero's zombie movies as a kid, and I was also a fan of an earlier film that inspired George: The Last Man on Earth, based on Richard Matheson's novel, I Am Legend. I always thought it might be fun to write a zombie book or perhaps a movie script, but I didn't want to steal Romero's flesh-eating, shoot-'em-in-the-head type zombies--that would be lazy. I wanted to invent a new type of zombie...and an original story angle that turned the more boring genre tropes on their heads. I was sick of the whole genre thing, and had almost stopped reading because mainstream books were all designed to fit in their little slots. Life does not fit into any genre, and my dream was to write a book that was as bizarre, as funny, and as disturbingly random as life.

So I thought: Throw out the tough-guy action hero. I would make my hero an underdeveloped, unhappy teenage girl--the Last Girl on Earth. You want zombies? I'll give you Xombies--but forget about shooting them in the head. My creatures would be unstoppable unless you minced them...and even then the mincemeat would come for you. But how would anyone escape such creatures?

Aye, there was the rub. How could anyone survive such a plague? But then it hit me: In a nuclear submarine! And this was very convenient because I knew a bit about submarines, having worked the graveyard shift at a submarine factory. I was always fascinated by subs and undersea technology, and I knew I wasn't the only one--the market was full of submarine thrillers. But nobody was writing about submarines filled with teenage refugees fleeing a zombie apocalypse. Nobody was writing about it from the perspective of a teenage girl.