As the trial approaches, Jay and Brian reflect on their involvement in the investigation and the impact they've had on Des, realising that regardless of their influence everything will be decided, as it always is, by a jury.
In 1983, a grisly discovery alerts Hornsey Police to a serial killer, operating under their noses for years. DI Peter Jay is stunned when civil servant Dennis 'Des' Nilsen admits to killing multiple men without knowing why.