A strong-willed psychologist tries to rehabilitate a member of a Pittsburgh street gang who has been found guilty of the murder of two other teenagers in a playground rumble.
Peter stows away on a ship from Italy, and arrives in New York, pursued by the ship's captain. He is advised that he will find other Italians in Little Italy, so he goes there, where Gepetto takes him in, after he attempts to steal some food. He tries to be good, but gets in trouble for stealing, so Jimmy the pizza man has to show him the way and get him to school. He thinks he isn't important, so he tells tall tales, scratching his nose each time. He tells people that Gepetto is a big important politician, so people automatically want to support him, though Gepetto is not running for anything.
Prominent gang leader Cyrus calls a meeting of New York's gangs to set aside their turf wars and take over the city. At the meeting, a rival leader kills Cyrus, but a Coney Island gang called the Warriors is wrongly blamed for Cyrus' death. Before you know it, the cops and every gangbanger in town is hot on the Warriors' trail.
A hard-nosed cop reluctantly teams up with a wise-cracking criminal temporarily paroled to him, in order to track down a killer.