The Lake District, 1899.

The Earl is dead and cruel Cousin Clarence has inherited everything. Twelve-year-old Lady Agatha Asquith is cast out of Gosswater Hall to live in a tiny, tumbledown cottage with a stranger who claims to be her father. Aggie is determined to discover her real identity, but she is not alone on her quest for the truth.

On the last day of the year, when the clock strikes midnight, a mysterious girl of light creeps through the crack in time; she will not rest until the dark, terrible secrets of the past have been revealed…