John Forrest is anticipating a quiet retirement spent penning detective fiction when he learns that a priceless collection of jewels belonging to a foreign potentate, Prince Homouska, has just vanished from the safekeeping of the Stamford Assurance Company. Aided by his butler, his Cockney assistant and his (initially) unwilling wife, Forrest sets out on the trail of the thieves.
| Actor | Role |
|---|---|
 Jack BuchananJohn Forrest | John Forrest |
 Googie WithersAlice Forrest | Alice Forrest |
 Edward Everett HortonTreadwell | Treadwell |
| SSyd WalkerYounce | Younce |
 Otto KrugerMike Chadwick | Mike Chadwick |
 Jack La RueAlberni | Alberni |
 Walter RillaPrince Homouska | Prince Homouska |
 David BurnsBeretti | Beretti |
 Charles CarsonCharles Cartwright | Charles Cartwright |
 Leslie PerrinsHarper | Harper |
 Ronald ShinerSpider Ferris | Spider Ferris |
| EEdward LexyInspector Elroyd | Inspector Elroyd |
 Ballard BerkeleyDetective in Nightclub | Detective in Nightclub |
| GGerald CaseFrank - Detective in Nightclub | Frank - Detective in Nightclub |
| RRobb WiltonBarman | Barman |
 Geoffrey SumnerFlats' Superintendent | Flats' Superintendent |
 Alec MangoEquerry | Equerry |
| RRoddy HughesPolice Photographer | Police Photographer |
 Eileen BennettCigarette Girl | Cigarette Girl |
| HH.F. MaltbyLarge Pompous Diner | Large Pompous Diner |
| JJohn MillerWaiter | Waiter |
 Jack MayMan Exiting Pub | Man Exiting Pub |