The Lake District, 1899. Twelve-year-old Lady Agatha Asquith is in turmoil. Her father, the Earl of Gosswater, is dead, and cruel Cousin Clarence has inherited everything. Agatha is cast out of Gosswater Hall to live in a small cottage with Thomas Walters - a stranger who claims to be her real father. Aggie is determined to discover her roots, but she is not alone in 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...
