Vincent and his wife, Annabel, move with their 10-year-old daughter, Shelly, to a new home, a massive building atop a hill that has been empty for some time. They are soon settled, but then Annabel discovers a diary belonging to a young girl, Hayley, who lived there previously. As she reads it, she becomes horrified when she learns of the things that took place here, and it is at this time, Shelly starts acting strange. An invisible friend comes into her life who depserately needs Shelly to find a special book for her. Shelly agrees and then a series of inexplicable events start occuring, all involving Shelly. Her parents soon realise they need more than a doctor. Terry is tired. Now that Agatha has recovered from her ordeal, Terry is losing faith in his ability to track down and stop Baal once and for all. And then he receives a call from Vincent and agrees to visit one last time. It doesn't take long for Terry to understand what is going on and makes a decision. This is going to end one way or the other. For good or bad.