The Hardest Word (1) A sadomasochistic serial killer is at large. The killings are brutal and the victims are found with the word 'Sorry' carved in their backs. Details Casts Title The Hardest Word (1) Genres Crime Mystery Drama Release Date 2004-08-08 Episode Runtime 01 Hours 00 Minutes Season Number 4 Episode Number 9 Production Companies BBC Drama Group Trevor Eve DCI Peter Boyd Sue Johnston Dr. Grace Foley Holly Aird Dr. Frankie Wharton Wil Johnson DS Spencer Jordan Claire Goose DC Amelia 'Mel' Silver