A wealthy lord dies and is entombed with a valuable deposit of jewels. Seven keys are required to unlock the tomb and get hold of the treasure. A mad doctor uses an iron maiden to systematically eliminate the heirs to the fortune.
| Production | John Argyle | Producer |
| Directing | Norman Lee | Director |
| Production | Hamilton G. Inglis | Production Manager |
| Editing | Ted Richards | Editor |
| Art | C. Gilbert | Art Direction |
| Camera | Alex Bryce | Director of Photography |
| Camera | Ernest Palmer | Director of Photography |
| Writing | Edgar Wallace | Novel |
| Sound | F. McNally | Sound Recordist |
| Writing | Gilbert Gunn | Screenplay |
| Writing | Norman Lee | Screenplay |
| Sound | Guy Jones | Original Music Composer |
| Directing | Roy Parkinson | First Assistant Director |
| Sound | Harry Benson | Sound Supervisor |
| Camera | Ronald Anscombe | Camera Operator |
| Sound | Guy Jones | Music Director |
