An investigation into the truths and myths behind an age-old ceremony.Throughout history, the practice of exorcism has been used for the purpose of driving out evil spirits and demons though to possess human beings and the places they inhabit. But there are more startling instances where exorcism has been used: to cure a trawler that seemed to be cursed; to expel demons from Bram Stoker's black 'vampire' dog' even to rid Loch Ness and the Bermuda...