An evil prince plans to use a super-explosive to take over the world.
| Actor | Role |
|---|---|
 Shirley MasonBarbara Hackett | Barbara Hackett |
 Buck JonesBrick McDonald (as Charles Jones) | Brick McDonald (as Charles Jones) |
 Richard TuckerHerbert Glenville | Herbert Glenville |
 Alan HalePrince Stefan de Bernie | Prince Stefan de Bernie |
 Walter McGrailDick Manley | Dick Manley |
 June ElvidgeEstelle Hackett | Estelle Hackett |
 Fred KelseyThe Submarine Commander | The Submarine Commander |
 Nigel De BrulierMordecai Newman | Mordecai Newman |
 Fred KohlerBarbara's Uncle | Barbara's Uncle |