- Writer:
- Eynon Evans
- Producer:
- Dafydd Gruffydd
- Designer:
- Alan Taylor
- Police Sergeant Bowen:
- Edward Evans
- Dr. Madoc Price:
- Philip Ray
- Mary, his daughter-in-law:
- Christine Pollon
- Gwyn Davies, a businessman:
- David Lyn
- Richard Dukes, an author:
- Emrys Jones
- John Harris, a civil servant:
- Richard Bebb
- Bernard Howells, a schoolmaster:
- Douglas Blackwell
- Albert Thomas, a builder:
- Glyn Houston
- Ann, Gwyn Davies's wife:
- Eve Lynn
- Annie Morris, a housekeeper:
- Madoline Thomas
- A Villager:
- W.H. Williams
- P.C. Thomas:
- Michael Forrest
- Detective-Sergeant Willis:
- Reginald Jessup
- Detective-Inspector Enoch Probert:
- David Davies
- A Police photographer:
- Michael Forrest
- A finger-print expert:
- Dillwyn Owen
