You cry out in surprise and begin to run - or, at least, try to run. Remember that rigor mortis? Bane of the undead, that. Your stiff legs creak, and your stick-like arms wave, and then your knees give way and you topple onto a pile of burning rubble. Just before your eyeballs go up in smoke you notice that the person behind you is actually a fellow member of the shuffling undead.
Did I mention that fire kills zombies?