Claude Pierce is delighted to be reunited in New York with his struggling architect father Jay when his mother Hilda leaves him for the sixth month's custody given Jay in their divorce. At his first day in a New York City public school, the aristocratic, English bred Claude becomes the butt of some childish practical jokes because of his polished manners, especially from "Gig" Stevens, whose father is going to the electric chair that night for murder, and Gig's pal, "Buck" Murphy. A few days later, when Buck accidentally throws Claude's football through a window, Claude takles the blame, but Mr. Crusenberry, the principal, punishes Gig and Buck for lying and the boys turn their anger towards Claude. To defend himself, Claude takes boxing lessons, and in a street fight with Buck, betters him, and wins his grudging respect. Gig goes to his aunt, Rose Hawley, a "kept" woman, to ask for money for a tombstone for his father, but because he doesn't want to tell her what the money is for, she is hesitant to give it to him. Buck and Gig try to steal to raise the money, but when they are unsuccessful, Claude suggests "stealing from the rich" like the fictional jewel thief Raffles and leads the boys to a vacant house to steal toys which Buck and Gig don't know actually belong to Claude. After they pawn the things, a policeman becomes suspicious and the boys are summoned to court. Though no theft has been reported, Claude reveals the truth. The judge puts Buck and Gig on probation, but not Claude because only Claude knew that they were taking things from his own home and not actually stealing. Angry, Buck and Gig refuse to have anything more to do with Claude. Before their first report to their probation officer, Buck and Gig decide to run away. Claude, who has caught a bad cold, determines to stop the boys, despite heavy rain, and sneaks out of his apartment and follows them to the cemetary where they have stopped to see the newly made tombstone. Claude tries to talk sense into the boys, but they won't listen. All three are soon picked up by a passing car that turns out to contain three crooks on the run. The crooks take the boys to a dinner and Claude speaks French to the French proprietor, telling him to summon the police. The boys escape during a shootout with police, but when Claude becomes delirious with fever, Buck and Gig take him to a doctor. After learning at the hospital that Claude has pneumonia, the boys decide to report to their probation officer. Hilda then arrives and sneaks Claude out to go to a better hospital and is distraught when she realizes that she has caused his condition to become critical. The boys go to Claude and tell him how much they have come to like him and an encouraged Claude recovers. Some time later, the now reformed boys are taken off probation and they happily ride bicycles with Claude, and are joined by Jay and Rose, who have started a new life.