Criminal Psychologist Rachel has her family brutally torn from her by a killer wanting to be known as Gabriel and sets out in search of the one responsible. This is, along with the help of her brother, Tony - who works the wrong side of the law and controls a majority of Manchester's criminal underworld. However, whilst on this path she agrees to help out an old friend, Detective Hunter, and is drawn into another case concerning a missing teenager and a paedophile ring run by the mysterious Pied Piper. But as she's drawn deeper into one case, Gabriel decides to resurface and takes Rachel into a world more deranged and twisted than she could ever have imagined possible.