His long term interest in poltergeists began with a visit, at of all times Halloween 1980, from a person who as a boy had been the centre of a poltergeist case 10 years before in St Catharines, Ontario. Clarkson admits he has never had a personal experience with a polt, but has interviewed many of the people involved in cases on both sides of the Atlantic, and presents a good selection of cases, including that Tina Resch and the infamous Enfield poltergeist. Another UK case was from Rochdale and featured the curious phenomenon of what seemed like rain appearing inside a house. Other cases are from Long Island, Connecticut, Florida, the Rosenheim poltergeist and the fifty year old Scottish case of Virginia Campbell.