It's just the end of the world

Some people go to exaggerated lengths to make other peoples life a misery, but when their equally miserable live comes to an end, they are never forgotten.
Sadi's life was just that. A misery. It was also a lie and a haunting and wherever she stepped, the land turned into a graveyard, but lets not go into great detail.
When the world ended, and survivors were left fending off the undead that would gladly devour human flesh and blood at any chance possible, one person came back. One person that would change the way Sadi would think and talk and act for the rest of her life in this unforgiving new world. One person that would linger like an angry spirit. One miserable being.