As many of us might know "Alien Greys" have been abducting humans for many centuries. For some reason at the beginning of the 20th century, they ended up in the employment of the Marcab Confederacy. Their job was to find out what frightened humans more than anything else. The results concluded that zombies scared people the most.
Once "The Zombie Apocalpse" had spread to the U.S. and the U.K., the Marcabs would appear and save the Earth from imminent destruction. From that point, conquest of Earth would be easy with the help of religious fundamentalists.
It's hard fathom the recent covert interference in the affairs of mankind. Fortunately, there are beings who are willing to defend man against high tech evil.
Have you got what it takes to defend the world against zombies? Check out the requirements at Zombieland.