A tough street kid attempts to rob a post office and is caught. In order to avoid reform school, he takes a job as a messenger with the post office. He finds that he likes it, and when his brother is released from prison, attempts to help his brother go straight. However, the two of them get mixed up with a local gangster, who has plans to start robbing post office branches and using the messenger and his brother to do it.

Jimmy Hogan, the leader of a gang of street kids who must fight for their existence, is arrested for robbing the Postal Telegraph Service when the police arrive in the middle of the robbery attempt. Feeling sorry for the boy, Kirk Graham, the district manager of the office and a former street kid himself, takes pity on Jimmy and offers him the choice of taking a job as a messenger boy or going to reform school. Jimmy takes the job, and after initial razzing by the members of his gang, he coerces them into enlisting. With Graham's help, Jimmy gets them jobs as messengers boys, and for the first time in their lives, the kids are treated with kindness and respect. Meanwhile, at home, Jimmy is disturbed that his sister Marge is mixed up with Chuck Walsh, a gangster who has promised to help get their brother Ed out of jail. Jimmy finally succeeds in convincing Mary to stop seeing Walsh and introduces her to Bob Pritchard, a fellow messenger. When Ed is released from jail, he joins Walsh's gang in a series of robberies of postal branches. When Walsh decides to rob Jimmy's office, however, Ed turns against his gangster friends to protect his brother. In the ensuing fight, Walsh shoots Ed and Jimmy races after the gangster. With the help of his fellow messengers, Jimmy brings the gang to justice, and for their honesty and bravery, the "little tough guys" are rewarded with motorcycles to use on their routes.