Raven Mysteries: Flood and Fang: Book 1 by Marcus Sedgwick
Meet the wonderfully weird Otherhand family and their faithful guardian, Edgar the raven, and discover the dark secrets of Castle Otherhand.
Edgar is alarmed when he sees a nasty looking black tail slinking under the castle walls. But his warnings to the inhabitants of the castle go unheeded: Lord Valevine Otherhand is too busy trying to invent the unthinkable and discover the unknowable; his wife, Minty, is too absorbed in her latest obsession - baking; and ten-year-old Cudweed is running riot with his infernal pet monkey. Only Solstice, the black-haired, poetry-writing Otherhand daughter, seems to pay any attention. As the lower storeys of the castle begin mysteriously to flood, and kitchen maids continue to go missing, the family come ever closer to the owner of the black tail...
Dedicated website on Raven Mysteries: www.ravenmysteries.co.uk