Ada Goth is the only child of Lord Goth. The two live together in the enormous Ghastly-Gorm Hall. It’s hard for her to make friends and, if she's honest, she's rather lonely. Then one day William and Emily Cabbage come to stay at the house, and together with a ghostly mouse called Ishmael they begin to unravel a dastardly plot. Ada and her friends must work together to foil the evil gamekeeper, Maltravers, before it's too late!