In Chernobyl, following the nuclear disaster, only a handful of people returned to their dangerously irradiated homes. On an uninhabited Scottish island, cattle live entirely wild. In Detroit, once America's fourth-largest city, entire streets of houses are falling in on themselves. From Tanzanian mountains to the volcanic Caribbean, Cal Flyn surveys the extraordinary places where humans no longer live, to give us a glimpse of what happens when mankind's impact on nature is forced to stop.