In this episode, savage forces sieze control from man. Thousands of domesticated animals break loose, feats of engineering will self-destruct, pets will escape, and a deadly virus will spread once again. Invasive vines will blanket the South, while the Sears Tower and Big Ben struggle to remain standing. In an outbreak of nature what will endure? It is a journey that will take us to the future of Chicago, Atlanta and London--as well as haunting locations already devoid of man. This isn't the story of how we might vanish--it's the story of what happens to the world we leave behind.