When their father commits suicide, Louis Lattimore and his sister, Ruby, are forced to move across the country at the behest of their mother, to a secret family estate tucked away among the sea islands of South Carolina. Louis is soon befriended by his two new neighbors and learns his new home is nothing like his old one in upstate New York. But it's not just culture shock Louis is wrestling. The locals seem convinced the family mansion is haunted. According to the local Gullah people, the manor is possessed by an insatiable spirit dubbed the Boo-hag. At the insistence of his new friends, Louis reluctantly seeks help from Auntie Caroline, an elderly member of the Gullah community revered to an almost supernatural status, and with good reason. Is she the only person who can help save Louis and Ruby from the Boo-hag?