The famous detective and his trusty side-kick, Tinker, are called in by the War Office to find some important papers that were stolen from a man killed during an air raid.
| Actor | Role |
|---|---|
 David FarrarSexton Blake | Sexton Blake |
 Manning WhileyRaoul Sudd | Raoul Sudd |
| DDennis ArundellJohann Sudd | Johann Sudd |
| JJohn VarleyTinker | Tinker |
 Betty Huntley-WrightNobby | Nobby |
 Gordon McLeodInspector Venner | Inspector Venner |
 Kathleen HarrisonMrs. Bardell | Mrs. Bardell |
 Cyril SmithBelford | Belford |
| MMagda KunYvonne | Yvonne |
 Ferdy MayneSlant-Eyes | Slant-Eyes |
 Charles FarrellSkipper | Skipper |
| RRoddy HughesFerraby | Ferraby |
| PPhilip GodfreyJames Baird | James Baird |
| TTony ArpinoTorch | Torch |
| CCharles RolfeMario Carloni | Mario Carloni |
| BBilly HowardPoliceman | Policeman |
| JJohn PoweCockney Chink | Cockney Chink |
| JJack VyvyanHawkins | Hawkins |
| HHenry WolstonAssistant Commissioner | Assistant Commissioner |
| DDavid KeirCharlie Kunn | Charlie Kunn |
 Elsie WagstaffMrs. Baird | Mrs. Baird |
| RRobert Brooks TurnerConstable | Constable |
| AAlfred HarrisHospital Doctor | Hospital Doctor |
 Margo JohnsHospital Nurse | Hospital Nurse |
 Jean SimmonsEva Watkins | Eva Watkins |
| MMark JonesBarman | Barman |