Blackie sees a robber jump into a taxi. After a car chase the robber gets away, leaving the taxi driver with a bullet in his arm. The taxi driver is an ex-convict, who Blackie once sent to jail. Blackie believes the taxi driver now to be an honest man and doesn't think he is mixed up in the robbery.
Nick Vincent, an out-of-work youth, takes advantage of a grocery store owner who thinks he's an armed robber when the young man demands prompt service with one hand jammed in his jacket pocket. Seeing how easy it was to steal nearly two-hundred dollars accidentally, Nick purchases a gun and plans to enter a life of crime. At Nick's father's request, Boston Blackie attempts to reason with Nick he can begin his one man crime wave.