Merchants hire a foreign criminal to kidnap a scientist for the secret of manufacturing diamonds.
| Actor | Role |
|---|---|
 Jack BuchananCaptain Hugh Drummond | Captain Hugh Drummond |
 Betty FairePhyllis Benton | Phyllis Benton |
 Juliette ComptonIrma Peterson | Irma Peterson |
 Allan JeayesCarl Peterson | Carl Peterson |
| AAustin LeighProfessor Goodman | Professor Goodman |
| FFrank GoldsmithSir Raymond Blayntree | Sir Raymond Blayntree |
| EEdward SorleyJulius Freyder | Julius Freyder |
| PPhil ScottSparring Partner | Sparring Partner |