When a woman begins to investigate her husband's mysterious death in a plane accident she discovers the involvement of a woman known simply as Diana.
| Actor | Role |
|---|---|
 Vincent BallBill Vernon | Bill Vernon |
 Betty McDowallJoan Scott | Joan Scott |
 Geoffrey TooneColonel Justin | Colonel Justin |
| CClare OwenPam Jennings | Pam Jennings |
 Marianne StoneMiss Green | Miss Green |
 Raymond AdamsonGeorge | George |
 Peter IllingKovali | Kovali |
 Richard CaldicotFisher | Fisher |
| BBasil BealeHarris | Harris |
 Dermot WalshPhil Scott | Phil Scott |
 Michael BalfourNewsagent | Newsagent |
 Tom GillPhotographer | Photographer |
| LLeon CortezCaretaker | Caretaker |
| CColin RixPolice Sergeant | Police Sergeant |
 Anthony BairdBarman | Barman |
| PPatsi KarrKovali's Secretary | Kovali's Secretary |
| DDenis HolmesSecurity Officer | Security Officer |
 Arthur EnglishPunter in Betting Shop | Punter in Betting Shop |