The Secret of Margrave Manor

When Edwina Margrave returns to Margrave Manor after receiving a package from her grandfather on her 20th birthday that contains a broken stone and a mysterious letter dated ten years ago, she discovers that her grandfather has vanished. She must now search the enigmatic old house room by room in search of clues that could explain his disappearance. Will she be able to find all the pieces to unlock the secret room, and if she does, will it reveal Margrave Manor's secret?