Nash and Grady cross paths with Nash's former foster parents, which triggers Nash's long-harbored vendetta towards them, particularly their little boy. Still coping with Jimmy Beck's death, the police bring Fitz in to help catch Nash.

Cast: Liam Cunningham, John Simm, Robbie Coltrane, Wil Johnson, Geraldine Somerville, Robert Cavanah, Ricky Tomlinson, Will Knightley, Jane Wheldon, Annette Ekblom, John Langford, Anthony Lewis, Dominic Rigby, Jim Whelan, Dave Hill