Synopsis by Hans J. Wollstein
Tough-guy actor (on-screen and off) Paul Kelly starred in this typical war-time serial about a police officer going undercover in order to smash a spy ring. The ring is led by fifth columnist Thyssen (Robert O. Davis), who has knowledge that the Americans are developing a secret formula for manufacturing synthetic rubber. Barton (Kelly) attempts to "steal" the formula and is captured by Thyssen. Joining the gang, he learns of their plans, which he immediately leaks to girl Friday Anne Nagel. Disguising himself as "The Black Commando," Barton manages to prevent the spy ring from stealing the formula, surviving the usual serial perils along the way. A flagrant attempt at duplicating the success of Republic Pictures' Spy Smasher (1942), The Secret Code nevertheless emerged as one of Columbia's better serial efforts, in no small way due to Kelly's taut performance and a surprising (for Columbia) lack of stock footage. The serial was released as a feature film overseas.