- Writer:
- Donald Wilson
- Music composed by:
- Ron Grainer
- Designer:
- Robert Macgowan
- Director:
- Dorothea Brooking
- Producer:
- Douglas Allen
- Martha Barlow:
- Julia Lockwood
- Dr Grant:
- John Rae
- Det-Insp Roger Stanton:
- Tony Britton
- Harold Chepstow:
- Stuart Hutchison
- Professor Adrian Small:
- Walter Horsbruch
- Miss Florence Pick, M.P.:
- Louise Lister
- John Ruthless:
- John Harvey
- Polly Arden:
- Lana Morris
- Mervyn Trott:
- John McLaren
- Floor Manager:
- David Ap Richards
- Freddie Walker:
- Scot Finch
- Joey Walker:
- Derek Francis
- Bertie Walker:
- Terence Alexander
- Sally Walker:
- Jacqueline Hill
- The Announcer:
- Armine Sandford
- Mrs Tindall:
- Olwen Brookes
- Mr Tindall:
- Robert Webber
- Mr Barrett:
- Ivor Salter
- Willie Walker:
- Andrew Sachs
- Wally:
- Wally Patch
