This clearly borrows heavily from The Exorcist and Don't Look Now which were both released a couple of years earlier to great acclaim. This isn't in the same league and is rather disappointing. A few well known faces do their best with their scripts but it is only worth watching if you are a huge fan of the genre, or Joan Collins or Donald Pleasance. Ralph Bates has acquired a dodgy Italian accent for no adequately explored reason, there's no real logic as to why his character needed to be Italian. This film I'm afraid is bit of a duffer.