The pressure is mounting on Detective Superintendent Dave Kelly (Stephen Graham) to make some arrests.
But Dave will not to be rushed or told what to do – despite the investigation constantly seeming to take one step forward and two steps back.
However, every time he has doubts, he thinks of Rhys’s mum and dad, Mel and Steve (Sinead Keenan and Brían F O’Byrne), and the torment they are going through.
The grieving pair are coping very differently, with Steve wanting to keep busy and get back to work, while Mel is unable to leave the house or face seeing anyone.
Meanwhile, on the streets of Croxteth, Liverpool, the pressure is also mounting as the intimidation of potential witnesses grows.