Cast 24

1. 

   Robert Beatty

   Bob Beacham

2. 

   Rona Anderson

   Mary Game

3. 

   Clifford Evans

   Tom Harmon

4. Edward Lexy

   Det. Insp. Charlton

5. 

   Olga Lindo

   Olive Tavy

6. Daphne Padel

   Self - The Twenty Questions Team

7. 

   Jeanne De Casalis

   Self - The Twenty Questions Team guest artiste

8. Jack Train

   Self - The Twenty Questions Team

9. Stewart MacPherson

   Self - The Twenty Questions Team

10. Norman Hackforth

    Self - The Twenty Questions Team 'Mystery Voice'

11. 

    Richard Dimbleby

    Self - The Twenty Questions Team

12. Harold Scott

    Maurice Emery KC

13. 

    Liam Redmond

    Echo News editor

14. Homi Bode

    Mohammed Ali

15. 

    Kynaston Reeves

    Gen. Maitland

16. Sonya O'Shea

    Stewart MacPherson's secretary

17. 

    Frederick Leister

    Police Commissioner

18. 

    Wally Patch

    Police Officer 'Tiny' White

19. 

    John Salew

    John Grimshaw

20. 

    Gordon McLeod

    Record News editor

21. Philip King

    Cheshire Cheese waiter

22. 

    Arthur Young

    Doctor

23. 

    Merle Tottenham

    Mrs. Tavy's Neighbour (uncredited)

24. Meadows White

    Frederick 'Ricky' Tavey (uncredited)

Crew 11