No one had time to think about what it was or how to react to it. With the energy of two million hydrogen bombs, the asteroid blasts through the atmosphere in a second—sweeping half the planet clean of all life. As a few lucky survivors stand in the darkness and look to the skies with gratitude for their lives, black snow starts falling and the great famine begins. It is 2012, and the world has changed forever. Shadow is a plains wolf who has always had food and shelter—all the things he needed to survive—until the great darkness arrived. The wolf is near death when a she-human happens upon him and frees him from his cage at the zoo. She and her dog Champ lead Shadow deep into the forest in a desperate attempt to survive. Eventually tragedy strikes, leaving Champ and Shadow alone. As Shadow and Champ venture high in the mountains, they discover a small wolf pack living on the carcasses buried under the soot-laden snow. As the sun returns and fresh buds form, Shadow must find acceptance within a new family.