Cast & crew
The Third Secret (1964)
Directed by Charles Crichton Written by Robert L. Joseph
Cast
| James Maxwell | Mark |
| Judi Dench | Humphries |
| Paul Rogers | Gillen |
| Sarah Brackett | Nurse |
| Patience Collier | Belton |
| Gerald Case | Mr. Vornick |
| Charles Lloyd Pack | Dermot |
| Freda Jackson | Bales |
| Peter Sallis | Jacks |
| John Adams | (uncredited) |
| Rachel Kempson | Mildred Fuller |
| Barbara Hicks | Mussburger's Secretary |
| Richard Attenborough | Alfred |
| Ernest Fennemore | Policeman |
| Alan Webb | Alden |
| Pamela Franklin | Miss Catherine |
| John Tatham | (uncredited) |
| Jack Hawkins | Belline |
| Nigel Davenport | Harding |
| Stephen Boyd | Beryl Stedman |
| Victor Hagan | Usher |
| Diane Cilento | Tanner |
| Ronald Leigh-Hunt | Police Officer |
| Geoffrey Adams | Floor |
| Peter Copley | Leo |
| Neal Arden | Morgan O'Mally |
Crew
| Douglas Slocombe | Director of Photography |
| Thomas N. Morahan | Production Design |
| Josephine Knowles | Production Secretary |
| Kenneth Mackay | Makeup Artist |
| Frederick Wilson | Editor |
| Charles Crichton | Director |
| Joan Davis | Continuity |
| Len Shilton | Sound Recordist |
| Richard Arnell | Original Music Composer |
| Shirley Bernstein | Associate Producer |
| Robert L. Joseph | Screenplay |
| Iris Tilley | Hairstylist |
| Terry Knight | Draughtsman |
| John McCorry | Wardrobe Master |
| Charles Crafford | Sound Editor |
| Chic Waterson | Camera Operator |
| Wally Milner | Sound Recordist |
| Davie Davison | Unit Manager |
| Peter Bolton | Assistant Director |
| Robert L. Joseph | Producer |