She would be an object in motion that would stay in motion, even if it meant flattening everything in her path. One cold fall day, high school junior Liz Emerson steers her car into a tree. Why? Why did Liz Emerson decide that the world would be better off without her? Why did she give up? This haunting, nonlinear novel pieces together the short and devastating life of Meridian High's most popular junior girl. Mass, acceleration, momentum, force?Liz didn't understand it in physics, and even as her Mercedes hurtles toward the tree, she doesn't understand it now. How do we impact one another? How do our actions reverberate? What does it mean to be a friend? To love someone? To be a daughter? Or a mother? Is life truly more than cause and effect?