1945. War has ended, but for sisters Isobel and Flora the struggles still continue. They've lost their father and had their home destroyed in a bombing raid, and now they must go to live with their aunt and her awful husband Mr Godfrey in their ancestral home, Splint Hall.

From the moment of their arrival it seems that this is a place shrouded in mysteries and secrets. Who are the strange men who arrive with packages at night? What is the source of the strange blue sparks coming from the ground? And why do the locals seem to hate their family so much? As the girls begin to unearth an ancient myth and family secret, the adventure of a lifetime begins.