- Writer:
- John Dickson Carr
- Producer:
- John Cheatle
- First Narrator:
- Bryan Powley
- Second Narrator:
- Edgar Norfolk
- M. de St. Mars, Governor of the Bastille:
- Stanley Lathbury
- The Abbe Giraut, Chaplain of the Bastille:
- Eric Lugg
- King Charles II:
- Malcolm Keen
- Henrietta, Duchesse d'Orleans, his sister:
- Cherry Cottrell
- King Louis the Fourteenth:
- Ernest Thesiger
- M. Hughes de Lionne, French Foreign Minister:
- Robert Farquharson
- Henry Bennet, Lord Arlington, British Secretary of State:
- Ronald Simpson
- M. Colbert de Croissy, French Ambassador to England:
- Cyril Gardiner
- Barbara Villiers, Countess of Castelmaine:
- Lydia Sherwood
- George Villiers, Duke of Buckingham:
- Ernest Jay
- The Sieur de Vauroy, King's Lieutenant at Dunkirk:
- Carl Bernard
- Maid of Honour:
- Jenny Lovelace
- Innkeeper:
- Amy Veness
