- Unknown:
- Gladys Young
- Unknown:
- Richard Hurndall
- Unknown:
- June Tobin
- Unknown:
- Norman Shelley
- Unknown:
- Lionel Marson
- Play By:
- John Keir Cross
- Novel By:
- John Dickson Carr
- Production By:
- Audrey Cameron
- The Presenter:
- Lionel Marson
- Superintendent John Cheviot:
- Richard Hurndall
- Taximan:
- William Eedle
- Cabbie:
- Harold Reese
- Flora Drayton:
- June Tobin
- Colonel Rowan:
- Baliol Holloway
- Mr Richard Mayne:
- James Thomason
- Mr Alan Henley:
- John Graham
- Margaret Renfrew:
- Joan Matheson
- Freddie Debbitt:
- Charles Hodgson
- Captain Hogben:
- David March
- Lady Cork:
- Gladys Young
- Lieutenant Wentworth:
- Peter Wilde
- Mr Robert Peel:
- Godfrey Kenton
- Vulcan:
- Norman Shelley
- Sergeant Bulmer:
- Ronald Baddiley
- Manton:
- Jeffrey Segal
- Sergeant Boyce:
- Harold Reese
