The yellow arrows on the pavement split to left and right, defining the acceptable movements of vehicles. And for a while, I’m immobilized, thinking of a butterfly flapping its wings. A typhoon I don’t want to create, so I sit in my car, studying the arrows. And I think then of my exhaust and of the Greenhouse Effect (especially because my particular automobile mocks emissions tests), and realize that not moving is a butterfly flapping its wings just as surely as turning is. And I’m jolted into action, but still haven’t made a choice. I shift my foot from the brake to the gas and the car leaps forward, splitting the arrows.