| Season | Episode Title | Air Date | Air Time | Channel | Country | #Creds | #Pics |
|---|
| Checkpoint | 03/13/1972 | | | UK | 8 | |
| 1 | Checkpoint, Part 2 | 03/14/1972 | 7:05 pm | BBC1 | UK | 7 | |
| 1 | Checkpoint, Part 3 | 03/15/1972 | | | UK | 7 | |
| 1 | Checkpoint, Part 4 | 03/16/1972 | | | UK | 7 | |
| The Defector | 03/20/1972 | | | UK | 9 | |
| 1 | The Defector, Part 2 | 03/21/1972 | 7:05 pm | BBC1 | UK | 8 | |
| 1 | The Defector, Part 3 | 03/22/1972 | | | UK | 8 | |
| 1 | The Defector, Part 4 | 03/23/1972 | | | UK | 8 | |
| Package Deal | 03/27/1972 | | | UK | 10 | |
| 1 | Package Deal, Part 2 | 03/28/1972 | | | UK | 9 | |
| 1 | Package Deal, Part 3 | 03/29/1972 | 7:00 pm | BBC1 | UK | 9 | |
| 1 | Package Deal, Part 4 | 03/30/1972 | | | UK | 9 | |
| The Contract | 04/05/1972 | 7:00 pm | BBC1 | UK | 8 | |
| 1 | The Contract, Part 2 | 04/06/1972 | | | UK | 6 | |
| A Visit from Hamburg | 04/07/1972 | | | UK | 9 | |
| 1 | A Visit from Hamburg, Part 2 | 04/08/1972 | | | UK | 7 | |
| Double Agent | 04/19/1972 | | | UK | 7 | |
| 1 | Double Agent: Part 2 | 04/20/1972 | | | UK | 7 | |
| 1 | Time to Kill: Part 1 | 04/26/1972 | | | UK | 10 | |
| 1 | Time to Kill: Part 2 | 04/27/1972 | | | UK | 8 | |
| 1 | Girl in Waiting: Part 1 | 05/05/1972 | | | UK | 9 | |
| 1 | Girl in Waiting: Part 2 | 05/06/1972 | | | UK | 9 | |
| 1 | Redmayne: Part 1 | 05/10/1972 | 7:00 pm | BBC1 | UK | 11 | |
| 1 | Redmayne: Part 2 | 05/11/1972 | | | UK | 9 | |
| 1 | The Executioner: Part 1 | 05/17/1972 | | | UK | 8 | |
| 1 | The Executioner: Part 2 | 05/18/1972 | | | UK | 7 | |
| 1 | The Executioner: Part 3 | 05/24/1972 | | | UK | 7 | |
| 1 | The Executioner: Part 4 | 05/25/1972 | 7:00 pm | BBC1 | UK | 7 | |
| 1 | Lorna: Part 1 | 05/31/1972 | | | UK | 12 | |
| 1 | Lorna: Part 2 | 06/01/1972 | 7:00 pm | BBC1 | UK | 10 | |
| 1 | Who Among Us?: Part 1 | 06/07/1972 | | | UK | 13 | |
| 1 | Who Among Us?: Part 2 | 06/08/1972 | | | UK | 10 | |
| 1 | Who Among Us?: Part 3 | 06/14/1972 | | | UK | 10 | |
| 1 | Who Among Us?: Part 4 | 06/15/1972 | | | UK | 10 | |
| 1 | Who Among Us?: Part 5 | 06/21/1972 | | | UK | 10 | |
| 1 | Who Among Us?: Part 6 | 06/22/1972 | | | UK | 13 | |
| 2 | Sullivan | 09/11/1973 | 8:15 pm | BBC1 | UK | 12 | |
| 2 | Anything Legal Considered | 09/18/1973 | | | UK | 12 | |
| 2 | The National Interest | 09/25/1973 | | | UK | 7 | |
| 2 | The Carrot and the Stick | 10/02/1973 | | | UK | 13 | |
| 2 | A Perfect Victim | 10/09/1973 | | | UK | 10 | |
| 2 | A Hero's Return | 10/16/1973 | | | UK | 10 | |
| 2 | Sale of Work | 10/23/1973 | | | UK | 11 | |
| 2 | Salvage | 10/30/1973 | 8:15 pm | BBC1 | UK | 11 | |
| 2 | Areas of Guilt | 11/06/1973 | | | UK | 12 | |
| 2 | Safe Conduct | 11/13/1973 | | | UK | 9 | |
| 2 | The Italian Link | 11/20/1973 | | | UK | 11 | |
| 2 | Dearly Beloved... and Dead | 11/27/1973 | | | UK | 13 | |
| 2 | Desperate Men | 12/04/1973 | 8:15 pm | BBC1 | UK | 11 | |
| 2 | A Dirty Sort of War | 12/11/1973 | 8:15 pm | BBC1 | UK | 10 | |
| 2 | The Mackten Circle | 12/18/1973 | | | UK | 10 | |
| 3 | Look for the Ugly | 03/21/1975 | | | UK | 9 | |
| 3 | The Cornet and the Beast | 03/28/1975 | | | UK | 13 | |
| 3 | A Nice Place to Live | 04/04/1975 | 9:25 pm | BBC1 | UK | 10 | |
| 3 | With Friends Like You | 04/11/1975 | | | UK | 8 | |
| 3 | Distant Relations | 04/18/1975 | | | UK | 11 | |
| 3 | To Kill a Unicorn | 04/25/1975 | 9:25 pm | BBC1 | UK | 6 | |
| 3 | Truth Won't Out | 05/02/1975 | | | UK | 9 | |
| 3 | April Sixty-Seven | 05/09/1975 | 9:25 pm | BBC1 | UK | 13 | |
| 3 | The Melioidosis Report | 05/16/1975 | 9:25 pm | BBC1 | UK | 4 | |
| 3 | The Merrin Memoirs | 05/23/1975 | | | UK | 6 | |