A riveting novel about a group of survivors on a hidden island utopia, where the truth isn't what it seems. Founded by the mysterious genius known as the Designer, the archipelago of Prospera lies hidden from the horrors of a deteriorating outside world. In this island paradise, Prospera's lucky citizens enjoy long, fulfilling lives until the monitors embedded in their forearms, meant to measure their physical health and psychological well-being, fall below 10 percent