When the news broke in May 2013 that three women had been held captive for over ten years in Cleveland, Ohio, the world was stunned. Not only had the women been imprisoned in an ordinary house a few blocks from where they had disappeared, but their captor, Ariel Castro, had never been a suspect in their kidnapping. The revelation sent shockwaves through the community and sparked widespread fear among the inhabitants of seemingly normal neighbourhoods everywhere. This is not a standalone case. In 2008, 42-year-old Elisabeth Fritzl emered from the cellar of her family home in Austria, having been imprisoned and raped by her father for 24 years. In the UK, the 'British Fritzl' held his two daughters captive for 28 years - moving frequently enough not to raise suspicion - and fathered seven children by them.