Z is a world void of safety. Of a society. Of factions, of peace between communities, of family drama and quests for revenge. Zombie stories are always about community, about the survivors pitted against the growing threat that is themselves, while toning the world around them down like a gamma bar - but not now. This world is dangerous, and never stops being so. There is no world building, no back plot to the characters and no two are alike. Z is how it is now. And "it" is never going to change.