- Author:
- Edgar Wallace
- Produced by:
- Leslie Stokes
- Divisional Detective-Inspector Wembury:
- Harry Hutchinson
- Central Detective-Inspector Bliss:
- David Smith-Dorrien
- Sam Hackitt:
- Frederick Piper
- Colonel Walford, Assistant Commissioner of Police:
- Arthur Young
- Maurice Meister:
- Peter Scott
- Doctor Lomond:
- John Laurie
- Cora Ann Milton:
- Marilyn Williams
- Mary Lenley:
- Freda Falconer
- John Lenley:
- Terry Morgan
- Station-Sergeant Carter:
- Eric Lugg
- Detective:
- Preston Lockwood
- Field:
- Eddy Reed