Jeannie feels the aggressive grimness of the Atlantic island even before her boat lands. Under the assumed identity of governess to young Varda, she has come to Langdon's Purlieu to investigate the mysterious death of her half-sister, the child's mother. Once in the house, she cannot understand why the servants seem perpetually frightened. 'Please, miss! ' the maid begs her. 'Leave this place! Leave before the blood moon rises over the sea! ' Can Jeannie unravel the secrets of the old house, or will she die in the attempt?