What two events in the park change Will in the novel, Hide & Seek?

• The first event in the park that has an effect on Will is the sight of the 'football' game being played there. He sees the ebb and flow of the game and recognizes a symmetry that he truly appreciates.

• A stray dog befriends him. He tries to shoo it away, but when it persistently sits beside him, seeking his attention, Will takes a rock from the water and beats the dog to death. He doesn't understand why he did it, only that it made him feel less angry.