When his mother eloped with an Italian opera singer, Louis Mazzini was cut off from her aristocratic family. After the family refuses to let her be buried in the family mausoleum, Louis avenges his mother's death by attempting to murder every family member who stands between himself and the family fortune. But when he finds himself torn between his longtime love and the widow of one of his victims, his plans go awry.
| Sound | Ernest Irving | Original Music Composer |
| Writing | Roy Horniman | Novel |
| Writing | John Dighton | Screenplay |
| Editing | Peter Tanner | Editor |
| Production | Michael Balcon | Producer |
| Writing | Robert Hamer | Screenplay |
| Directing | Robert Hamer | Director |
| Camera | Douglas Slocombe | Director of Photography |
| Art | William Kellner | Art Direction |
| Costume & Make-Up | Harry Frampton | Makeup Artist |
| Costume & Make-Up | Barbara Barnard | Hairstylist |
| Writing | Nancy Mitford | Screenplay |
| Costume & Make-Up | Anthony Mendleson | Costume Design |
| Editing | Roy Baker | Assistant Editor |
| Camera | Jeff Seaholme | Camera Operator |
| Costume & Make-Up | Pearl Orton | Hairstylist |
| Costume & Make-Up | Daphne Martin | Hairstylist |
| Production | Leigh Aman | Unit Production Manager |
| Production | Michael Relph | Associate Producer |
| Directing | Norman Priggen | Assistant Director |
| Editing | John Jympson | Assistant Editor |
| Art | Bert Davey | Assistant Art Director |
| Crew | Sydney Pearson | Special Effects |
| Costume & Make-Up | Ernest Taylor | Makeup Artist |
| Production | Hal Mason | Production Supervisor |
| Editing | Seth Holt | Editorial Services |
| Crew | Geoffrey Dickinson | Special Effects |
| Sound | Wolfgang Amadeus Mozart | Music |
| Sound | Stephen Dalby | Sound Director |
| Directing | Phyllis Crocker | Continuity |
| Sound | Ernest Irving | Conductor |
| Sound | John W. Mitchell | Sound Recordist |
| Sound | Philharmonia Orchestra | Music |
