Taking a break from Republic's "Higgins Family" series, Russell Gleason plays the title character in Monogram's Undercover Agent. A humble railroad postal clerk, young Bill Trent (Gleason) aspires to be an inspector. To this end, he carries a gun "just for emergencies," a fact that eventually gets him into trouble with his authorities. Hoping to redeem himself, Bill offers to help the Feds round up a gang of sweepstakes-ticket counterfeiters. Those grand old barnstormers J. M. Kerrigan and Maude Eburne steal the show as, respectively, a boozy ham actor and a neighborhood harridan. Shirley Deane, then Mrs. Russell Gleason, fulfills the film's leading-lady responsibilities.