John Loder and Elliot Makeham star in Redd Davis’s British topical crime thriller. Professor Grayson is working on an anti-gas experiment and Dr. Klee, whose quiet advertising covers other welfares, means to find it.
| Actor | Role |
|---|---|
 John LoderCapt. Rufus Grant | Capt. Rufus Grant |
 Noel MadisonDr. Klee | Dr. Klee |
| BBelle ChrystallNora Grayson | Nora Grayson |
| LLeonora CorbettHerlaine Frank | Herlaine Frank |
 Jerry VernoHugo Guppy | Hugo Guppy |
| DDavina WhitehousePolly | Polly |
 Eliot MakehamProfessor Grayson | Professor Grayson |
| AAlexander SarnerMr. Vander | Mr. Vander |
| MMelville CrawfordPete Voss | Pete Voss |
 Nigel BarrieColonel Lockwood | Colonel Lockwood |
| CCarl MeleneMonsieur Buckner | Monsieur Buckner |