Let's see, people getting a virus that kills them. Then once they are dead they come back to life. Then they all of a sudden crave brains. No one knows why. They are already dead. They don't need brains to live. They just want them. Oh wait that is how it was originally. Now they just eat people. So they have become cannibals. Cannibals that need to eat for no reason at all. For some reason shooting their brain kills them. They don't have a heart beat, they don't breath air, it doesn't hurt them if you chop them into pieces. Only if you damage the brain. Yeah seems really logical. Definitely going to happen.