When Zombies Attack

You grab hold of the sledgehammer and bust the door to pieces. Stepping over the rubble, you head into the hallway and begin marching down the stairs. At the foot of the stairs stands an unsuspecting zombie, which sees you a few seconds too late, for you swing your sledgehammer and connect with it's grotesque head, sending it twirling into the wall. Down the hallway you see a door that leads outside into the city, which is infested with zombies. You begin to walk towards the exit, when you hear a chattering noise coming from the zombie's head.