Jim O'Malley, a patrolman who is a stickler for the letter of the law, is assigned to duty as a traffic cop near a grade school, where he meets Lucille Thayer, a beautiful teacher. Jim becomes a favorite with the children and arranges for Margie, a little lame girl, to be in the care of a surgeon. Jim discovers the hideout of a gang of bootleggers and sets up a raid that nets all but Herbert Browne, the gang's leader. Jim later recognizes Browne during a party at Lucille's house and place him under arrest, only to discover that he is her fiancé. In a spirit of self-sacrifice, Jim lets Browne go and allows himself to be dismissed from the force. Danny the Dude, Margie's father, whom Jim sent to prison, is released and, learning of Jim's kindness to Margie, exposes Browne as the leader of the bootleggers. Jim's sacrifice then becomes known, and he is reinstated to the force with honors, winning Lucille's love for his many kindnesses towards her.