- Writer:
- Eric Maschwitz
- Producer:
- W. Lyon-Shaw
- Settings:
- Richard Wilmot
- Jocelyn Cullum:
- Honor Blackman
- Colin Currie:
- Donald Houston
- Lady Currie:
- Henzie Raeburn
- Superintendent Harington:
- Arthur Rigby
- Sir Olive:
- Robert Raglan
- Williams:
- Basil Appleby
- Todd:
- Edward Evans
- Professor Deller:
- Joseph Fischer
- Martineau:
- Wensley Pithey
- Mabel:
- Gillian Owen
- Commander Hilliard:
- Philip Lennard
- Miss Hale:
- Judith Furse
- Miss Hedges:
- Joan Lovelace
- Vinsen:
- Michael Godfrey
- Newspaper editor:
- Jock McKay
- Mr. Thompson:
- John Rutland
