what prompts Henry to run in the direction of battle

As Henry wanders through the forest, he hears loud crashes and roars through the darkening sky. It seems as if the world is being rent asunder. Henry's mind is going in all directions at once. He feels that the two armies are going at each other in a panther-like fashion. He then runs, ironically, in the direction of the battle, more to witness the collision of the armies than to participate.