Violet is the daughter of a woman who is working as a Medium in London in 1872 at the height of the Spiritualist craze. Her mother is a fraud (or charlatan in Victorian terms) but Violet has not option but to assist her. They are invited to a English Country weekend by Sir Jasper and, once there, Violet really begins to see ghosts. They scare her witless because she doesn't believe in ghosts. But one very persistent one wants Violet to solve her murder. Great introduction to gothic novels for young adults.
