The third novel featuring national park ranger Anna Pigeon finds her dealing with three mysteries in Colorados Mesa Verde National Park: an inexplicable illness thats infecting visitors, a childs mysterious death, and the murder of a friend. Reissue. nLately, visitors to Mesa Verde have been bringing home more than photos--theyre also carrying a strange, deadly disease. And once it strikes, park ranger Anna Pigeon must find the very human source of the evil wind.