Twenty-five years ago, planes dropped from the sky and ships ran aground, empty, signaling that Ireland was irretrievably cut off from the rest of the world. The Sídhe, ancient fairy folk, had vowed revenge upon the country that exiled them from their homes thousands of years ago. Their retribution is brutal: every adolescent will at some point be called to the Grey Land, where they’ll have to flee, fight, and hide for survival. For them, the ordeal lasts a little over a day. For their friends anxiously watching back home, it’s all over in three minutes. Almost no one survives.