In this episode, best-selling author Mark Billingham takes a fresh look at two of Britain's most infamous serial killers, Ian Brady and Myra Hindley, who murdered five children between 1963 and 1965.Sentenced to life imprisonment, Brady and Hindley were masters at staying in the public eye even behind bars. Astonishingly, the pair were allowed to communicate whilst imprisoned and they both also corresponded with journalists and supporters in the outside world. Billingham unravels the couple's twisted relationship, from loving devotion to bitter hatred.