Near destitute after death of her husband, a widow and her young children are approached by an elderly and mysterious solicitor, Mr Blunden, who asks the family to become caretakers of a derelict, partly fire damaged country mansion. The family take up the offer and shortly after moving into a small cottage on the mansion’s estate the youngsters, Jamie and Lucy meet up with a pair of ghosts, Sara and Georgie, two children who were killed in the fire at the mansion one hundred years ago. The spirits recount the tale of their wicked housekeeper, Mrs Wickens, whom they suspect plotted their murder in order to gain their heritance. Aiming to solve the mystery and hoping to help their new friends along the way, Jamie and Lucy concoct a potion allowing them to travel back in time to the night of the tragedy, where they discover Mr Blunden’s involvement in the dramatic events of the fateful night.