Many, many zombies stories make the mistake of trying to make zombies have a rational explanation. Here’s the thing, zombies don’t make sense. I know, I write about them, and I read about them… but I have only ever read a single zombie book (and seen a single zombie movie) that did a decent job of explaining zombies. I will talk about that in a minute, but first I’m going to talk about how I handle the issue and how I think it should be handled.
So, first things first – in Night of the Living Dead Romero fucked up. I hate saying that, because I love Romero and all of his work, I think he does an amazing job with details, and with themes, but he fucked up this time… he suggested the zombies were the result of cosmic radiation. Note, he refuted that in all subsequent movies, and many people have said that it wasn’t the cause, just what the news anchor thought might be the cause, but let’s face it, Romero was going that direction. It wasn’t definitive, so people have taken it in another direction.
In the sequel, the brilliant Dawn of the Dead, Romero makes it much more ambiguous, dropping the cosmic rays theory in favour of the line that “When there is no more room in hell the dead return to consume the living”. That isn’t meant to be the explanation, but it is used in the movie. A preacher says it on the radio at one point. It’s great, incredibly well used, and represents people not having answers, a theme that continues throughout the rest of the series.
In the end, leaving the characters without those answers makes far more sense. Usually, a half-assed explanation for zombies takes people out of the story, and it really doesn’t add anything at all.
One important note: this is about zombies, reanimated corpses coming back to feed on the living. It doesn’t apply to stories like 28 Days Later. That’s a disease. The “zombies” aren’t actually dead. Interestingly enough, Romero was also the pioneer of that genre with the 1973 film The Crazies but always viewed it as separate from zombies.
I have only ever seen one zombie movie that made the zombie infection make sense, as I mentioned above. It was both a movie and a book, although they were written at the same time. The movie is The Girl With All the Gifts. They used cordyceps, an invasive fungus that takes over the host body, basically running it without the permission of the host. It’s terrifying because for once it is something plausible. Cordyceps could look like a zombie, especially if they spread spores through the saliva. They would be creatures who looked human, but their internal structures would be nothing, just a skeleton for the cordyceps to work on. That’s the only semi-realistic explanation for zombies I’ve ever seen.
There are other issues with zombies as well. The majority of the population would have to turn, and fast, for zombies to be any kind of a threat. I mean, they are slower, dumber, weaker. They would have to be the majority. In my World of the Dead series I got around that by having seventy percent of the living become zombies overnight, from that point most people died, and yet humanity is still probably going to win in the long-term… we are smarter and more versatile.
I do have a plague story planned as well, for someday. It’s nothing soon, but I have figured out the characteristics that would make that kind of global plague a genuine threat.
Anyway, unless you are ML Carey, don’t explain your zombies. It will damage your story.