Originally Posted by
Fhloston
That's what sets WD apart from other zombie series. It's almost always the obligatory virus that turns us. On WD, people just started turning after death, all of a sudden. Was it something in nature? Maybe a vaccine?? Not knowing adds more to the story, and the characters trying to figure out what went wrong.
Pretty similar to Attack on Titan's plot. You find out as the story progresses, and it just gets more and more fucked up as new details emerge. Makes it more interesting for me, at least.