There are lots of movies, books, and TV shows with hypothetical, terrible situations where zombies, aliens, mutants, or vampires somehow takeover the world. It all seems hilariously improbable (OR DOES IT?!), but stranger things have happened, amiright?
What stranger things, you ask? How about that time that female astronaut drove a million miles to kill her boyfriend, all while wearing an adult diaper? How about the Heaven's Gate cult? How about the Buffalo Bills almost winning a Superbowl about 17 times? SEE, THIS IS A CRAZY WORLD WE LIVE IN. VAMPIRES COULD TOTALLY TAKE TO THE STREETS, HOWLING FOR UNDEAD BLOOD.
And when they DO, you've gotta be prepared, right? Check out this Vampire Combat Manual ($10.20, Amazon), which will supposedly help you fend off the creatures, like in that upsetting Halloween episode of The Simpsons.