Marian and her sister Laura live a quiet life under their uncle’s guardianship until Laura’s marriage to Sir Percival Glyde, who is a man of many secrets. Could he be connected to the strange appearances of a young woman dressed all in white? And what does his charismatic friend, Count Fosco—whose white pet mice enjoy running in and out of his waistcoat—have to do with it all? Marian and the girls’ drawing master, Walter, must turn detective in order to uncover the truth and to protect Laura from a fatal plot.