From the moment her mother becomes pregnant from a seemingly spontaneous conception, Mary Jo Cassler senses a change in her otherwise normal family. And it isn't long after Bella Mae is born that Mary knows there is something odd about her sister. She's much too intelligent for her age and seems to possess unexplainable abilities. Others in their small town of Pedeck, Alabama seem to notice it as well and start to peg Bella Mae as a demon. Mary is warned that if she helps her, the world will end. Mary is torn between the love and trust she has for her sister or the possibility that the rumors and warnings may be true.