Greyfrair's Cemetery in Edinburgh has a centuries old reputation for being haunted.Its gruesome history includes use as a mass prison, headstone removal, witchcraft, bodysnatching, desecration, corpse dumping and live burial. In 1998, something new and inexplicable began occurring in the graveyard.Visitors encountered 'cold spots', strange smells and banging noises.They found themselves overcome by nausea, or cut and bruised by something they could not see.Over the space of two years, twenty-four people were knocked unconscious.Homes next to the graveyard wall became plagued by crockery smashing, objects moving and unidentified laughter.Witnesses to these attacks ran into the hundreds. There were two exorcisms of the area. Both failed. The section of Greyfriars where the attacks occurred is now chained shut.The entity responsible has been named the 'Mackenzie Poltergeist'.It has become one of the best-documented and most conclusive paranormal cases in history. The Poltergeist is still growing stronger. This is its story.