This is the story of a family called the Perrys and the terror they bring to the small mountain resort town of Scotland Lake. Alex Perry is the latest in a long line of Perrys stretching back to the mid-17th century, when an English rascal named William Stiles St. Jean Perry was forced out of England and came to the New World to prey on the settlers there. What Alex doesn’t know is that he and all his male ancestors since William's time are the offspring of a demon which took possession of William's body just before he landed in Carolina. Thus begins an unending nightmare of anguish and horror for all his friends and family. And it’s not the Lake's first experience with a string of unsolved murders. There follows a period of terror and frustration as the people vent their passions on each other. It has been a slack tourist year and money is short. There's a recession and a gasoline crisis. People are angry and edgy. Through all of this, Alex has been bothered by recurring periods of illness and a kind of “double vision." He imagines and remembers things that make no sense, images of brutality and cruelty that spring full-blown, completely unbidden from some source deep inside his memory. It turns out that these memories are from past lives and excesses of the demon. Let loose upon the people of the Lake, the Perry demon is an awesome, malignant evil, hellbent on revenge for being rousted out of its home, determined to force or trick its way back into Alex Perry, now protected by a mystical token-- an iron pendant. In the climactic final part of the story, when it seems there is no other way, Alex finally accepts what must be. In order to spare the town any more destruction and to protect his family from further depredations, he voluntarily allows the demon to re-enter his body. Events swiftly follow as Police Chief Dick Mosley and a squad of townspeople realize it isn't their original suspect they should be following but Alex Perry. A long perilous pursuit through the woods and hills around the town eventually leads them into Cathedral Caverns, where the Perry-thing has taken refuge. They must contend with the confusing twists and turns of that labyrinthine complex as well as with the fact that Alex's wife and children are also following him and will be in mortal danger if they find him before Mosley's men do. In the end, Alex is trapped in the chamber of a spectacular waterfall. He is cornered and Mosley hopes to coax him down. Against their will, Mrs. Perry and the kids are escorted back up to the surface. There is very little of the original Alex left in the beast, but there is just enough to outwit the thing one last time. But the epilogue shows us just how fleeting our relief may be.