Newly minted postal inspector William Trent inadvertently violates his department's strict regulations and receives a three-month suspension. While on leave, he becomes suspicious of a popular sweepstakes being run by a bookie named Bartel. Trent tips off his supervisor, who recommends that the suspended agent go undercover and monitor the operation. William develops a personal interest in the phony gambling venture. His fiancee's cash-strapped father is under Bartel's thumb, and clamping down on the racket might put the old man's in life in jeopardy.
Russell Gleason and Shirley Deane, clean-cut youths previously teamed in 20th Century Fox's "Jones Family" series, reunited under the auspices of independent producer E. B. Derr in this low-budget melodrama distributed by Monogram Pictures. Quickly and efficiently made, Undercover Agent was rushed into theaters to capitalize on recent publicity generated by the apprehension and prosecution of numerous organizers of fraudulent sweepstakes operations. Howard Bretherton's direction keeps the story moving briskly, and Gleason - mostly seen in Andy Hardy type roles - is surprisingly convincing as the eager-beaver postal inspector.