When Cora and her little sister Mimi are sent to live with their great aunt Ida, who they have never met before, they quickly come to realise that they are not welcome. Already in a difficult situation, with an absent mother and a father who is too busy to care for them, they must also deal with their eccentric aunt and an enormous, intimidating and ruinous old house which holds many secrets, which Cora in particular comes to realise will become a direct threat to their safety. Without the kind attention of their neighbours, their stay would be intolerable. Why is it that village children are not permitted to go anywhere near the old church, and why is it that Aunt Ida insists that all doors and windows in the house are bolted and never opened? Why too does she insist that Mimi must never be left alone? As Cora and her friends delve deeper into these mysteries, they uncover an age old secret that has threatened the safety of village children for generations. It is a malevolent threat that is alive even to the present day. As danger creeps closer and closer, many of the main characters attempt to thwart the growing threat, with varying degrees of success. What follows is a gripping finale, sure to rattle the boldest reader.