When Zombies Attack

You smash the zombie's face in, and it sends the head flying of the body. With your knowledge of zombies, you know that without a head, the zombie is useless. [Hence why in the movies, kids, they shoot the zombie in the face.] You think, you've won that battle, but what lies ahead? You continue walking and you find a door to an office. There is a bin in there, and you think it may have weaponry. But you see a zombie locked inside... You..