When Nona's guardian kills himself, she is immediately suspected of murdering him. In a world where nature and darkness are feared, where wild animals are killed or held captive and cities are illuminated by permanent light, who will believe her innocence? Nona must flee with her only friend - a bear who is strangely human. In their desperate attempt to escape capture, Nona and her bear encounter two strange boys, Caius and Jay. Together, the four of them will hide, and fight, and make the deadliest of enemies in their desperate race to a forbidden place called The Edge.