Guest Stars Mark Bonnar as Piers Christie Amanda Drew as DI Reid Adam James as Dr. Richard Fell Lashana Lynch as Shona Benson Freya Parker as Mary Smith Bill Ward as Hearns Alexander Newland as Flynn Bryan Dick as Lucas Ballinger Davood Ghadami as Ali Kolahi Ashley Chin as Mark Benson Bryony Afferson as Petra Smith Wendy Albiston as Stacey Greggs Deshaun Strong as Darius Benson Sammy Kissin as Ellisabet Vrinska Sean Jackson as Roper Matthew Owens as Firefighter