In 1986 there was a nuclear disaster at Chernobyl, in what was then the Soviet Union. The area, over two thousand square kilometres, was evacuated and sealed, closed off from the world by a massive wall. But 149 school kids are left behind, forgotten. Over time, they learn how to survive, and slowly they build a society for themselves despite the dangers – radiation, wolves, and winter – of the Zone. Twenty years after the Evacuation, a helicopter from the other side of the Wall appears, with a mysterious woman at the controls. That encounter sparks a chain of events which takes one of the Children, the hunter Isaak, back to the past, to the day of the Evacuation – and towards a confrontation which threatens the future of the Zone itself.