Guest Stars Idris Elba as Robert Gabriel James McAvoy as Gowan Ross Camilla Power as Joanna Sydeham Ron Donachie as John Ross Gary Cross as Sergeant Lonan Ronald Pickup as Sir Stuart Stinhurst Naomi Frederick as Elizabeth Julian Wadham as David Sydeham Don Gallagher as Inspector Macaskin Yvonne O'Grady as Joy Barbara Horne as Solicitor Ravin J. Ganatra as Forensic Pathologist Jonathan Firth as Rhys Davies Jones