The pavements are cracking, the earth is shaking and the Night People are coming to the surface. Deep beneath the ground an ancient power is stirring; bringing with it terrible danger to St Savlons. From the writer of Dragonfire and Juggler of Shapes comes the latest story of Polly and Courtleigh. Faced by their deadliest enemy, they must work together to save themselves and their friends before it is too late ...