Novelist and amateur sleuth, Paul Temple, meets a newspaper woman called "Steve." Together they investigate a gang of diamond robbers.
| Actor | Role |
|---|---|
| AAnthony HulmePaul Temple | Paul Temple |
 Joy SheltonSteve Trent | Steve Trent |
 Tamara DesniDiana Thornley | Diana Thornley |
 Jack RaineSir Graham Forbes | Sir Graham Forbes |
 Beatrice VarleyMiss Amelia Marchment | Miss Amelia Marchment |
| HHylton AllenDr. Milton | Dr. Milton |
 Maire O'NeillMrs. Neddy | Mrs. Neddy |
 Michael GoldenDixie | Dixie |
| RRichard ShayneChief Inspector Richard Dale | Chief Inspector Richard Dale |