| Name | Character | Episodes |
|---|---|---|
| Harry Towb | 2 | |
| Frazer Hines | 1 | |
| John Carson | 1 | |
| George Coulouris | Dr. Bennett | 1 |
| Richard Carpenter | Dr. Lowden | 1 |
| Barbara Shelley | 1 | |
| Geoffrey Bayldon | 1 | |
| Richard Marner | Dr. Bemmelman | 1 |
| William Russell | John Richards | 1 |
| David Graham | Mr. Mehta | 1 |
| Desmond Llewelyn | President of the Court | 1 |
| Desmond Llewelyn | Ian MacDonald | 1 |
| Desmond Llewelyn | Company Spokesman | 1 |
| Jean Anderson | Miss Reid | 1 |
| Michael Sheard | 1 | |
| Roy Holder | 1 | |
| Bernard Archard | 1 | |
| Bernard Archard | Mr. Wales | 1 |
| Glyn Houston | 1 | |
| Neil McCarthy | 1 | |
| Hilary Mason | 1 | |
| Faith Brook | Carolyn Manningham | 1 |
| Richard Leech | Dr. Nicholson | 1 |
| Derek Waring | 1 | |
| Margaret John | Mrs. Powell | 1 |
| Michael Culver | Robin Gregson | 1 |
| Jennifer Daniel | Jane Callon | 1 |
| Hana Maria Pravda | 1 | |
| Mona Bruce | 1 | |
| Tom Watson | 1 | |
| George Murcell | 1 | |
| Roddy McMillan | 1 | |
| Richard Bebb | Dr. Maynard | 1 |
| Rachel Thomas | 1 | |
| Kevin Stoney | 1 |