Together with investigative journalist Fiona Walker, David uncovers two family annihilations that occurred on the same day in Scotland in 2008. Fiona travels to Buckhaven in Fife, where Rab Thomson killed his son and daughter in their home, to uncover the events leading up to the murders, while David is in the Campsie Fells, where Ashok Kalyanjee took the lives of his two sons.