Bobby Jones y Lady Frankie Derwent intentan resolver un misterio a partir de las últimas palabras de un hombre moribundo.
 | Francesca Annis | Lady Frances Derwent |
| John Gielgud | Reverendo Jones |
| Bernard Miles | Dr. Thomas |
| Eric Porter | Dr. Nicholson |
| Leigh Lawson | Roger Bassington-ffrench |
| James Warwick | Bobby Jones |
| Madeline Smith | Moira Nicholson |
| Connie Booth | Sylvia Bassington-ffrench |
| Robert Longden | Badger Beadon |
| Doris Hare | Rose pratt |
| Joan Hickson | Mrs. Rivington |
