- Author:
- Edgar Wallace
- Production:
- Royston Morley
- Divisional Detective Inspector Wembury:
- Harold Warrender
- Central Detective Inspector Bliss:
- Ralph Truman
- Colonel Walford:
- Neville Brook
- Samuel Hackitt:
- Ivor Barnard
- Maurice Meister:
- Franklin Dyall
- Dr. Lomond:
- Henry Oscar
- Cora Ann Milton:
- Judy Kelly
- Mary Lenley:
- Lydia Sherwood
- John Lenley:
- Norman Claridge
- Station-Sergeant Carter:
- Joe Cunningham
- Benny:
- Peter Ashmore
- Policemen and Detectives:
- Richard George
- Policemen and Detectives:
- David Storm
- Policemen and Detectives:
- Reginald Peldon
- Mrs. Hackitt:
- Phyllis Morris
- P.C. Field:
- Eric Noels
