Japanese spies attempt to subvert America's war effort; G-Men attempt to thwart their plot.
| Actor | Role |
|---|---|
 Rod CameronRex Bennett | Rex Bennett |
 Roland GotChang Sing | Chang Sing |
 Constance WorthVivian Marsh | Vivian Marsh |
| NNino PipitoneOyama Haruchi | Oyama Haruchi |
 Noel CravatRanga | Ranga |
 George J. LewisLugo | Lugo |
 Maxine DoyleMarie [Ch. 8] | Marie [Ch. 8] |
 Donald KirkeMuller - Pier 17 Thug [Ch.1] | Muller - Pier 17 Thug [Ch.1] |
 Ivan MillerPier 17 Customs Inspector [Ch.1] | Pier 17 Customs Inspector [Ch.1] |
 Walter FennerWilliams - Financial Agent [Ch.1] | Williams - Financial Agent [Ch.1] |
 C. Montague ShawProf. Nicholson [Ch. 3-4] | Prof. Nicholson [Ch. 3-4] |
 Harry BurnsTony Mills [Ch. 4, 12-13] | Tony Mills [Ch. 4, 12-13] |
 Forbes MurrayJames Kennedy [Ch. 12] | James Kennedy [Ch. 12] |
 Hooper AtchleyHarrison J. Caldwell [Ch. 5] | Harrison J. Caldwell [Ch. 5] |
 Robert HomansCapt. Gorman [Ch. 12-13] | Capt. Gorman [Ch. 12-13] |
| AAllen JungFuji - Escaped Japanese Spy [Ch.2] | Fuji - Escaped Japanese Spy [Ch.2] |