Back Side of the Backlight

The story revolves around Elizabeth, the youngest daughter of a wealthy family who was sent to a convent as a child. After the death of her parents, she returns to the family mansion, where she is welcomed by her older sister, Isabella, the heiress of the earldom. Elizabeth begins to notice strange things happening at the mansion and suspects that Isabella is hiding a dark secret. What is hiding behind Isabella's beautiful but frightening face?