In New York’s East Side, a tight-knit youth gang led by Muggs McGinnis — along with Danny Collins, Glimpy Stone, Scruno, Skinny, and Peewee — find themselves falsely arrested after the truck they were riding in is stolen. The boys are remanded to Wilton Reform School, where Muggs, the streetwise leader, earns the nickname “Mr. Wise Guy” from the brutal guard Jed Miller. The arrival of the new warden, Jim Barnes, shifts the tone of the institution. Barnes reassures Bill Collins, Danny’s older brother who carries painful memories of the school from his time as a guard there, and he gives Bill a guided tour of the grounds. Barnes’s secretary, Ann Mitchell, accompanies them, and what begins as a formal tour gradually softens into a chance encounter that leads to a dinner outing for Bill and Ann.
That evening, a darker thread pulls Bill away from personal interests when he stops by a drugstore to buy cigarettes. A swift night of crime unfolds as escaped convict Luke Manning robs the shop, murders the clerk, and abducts Bill, forcing him to help chase the thief. Manning manages to escape when Bill’s car crash ends the pursuit, and Bill is subsequently convicted of robbery and murder, facing execution despite his earlier testimony about reform-school cruelty.
Inside the reform school, the boys tangle with two hard-edged troublemakers, Rice Pudding Charlie and Chalky Jones. When Barnes witnesses Jed Miller egging on a fistfight, he insists on Miller’s resignation, signaling a potential shift toward accountability. Chalky tries to derail the boys by informing Barnes of their plans to run away, but Barnes punishes Chalky for being an informer, establishing a fragile code of honor within the ranks.
Newsreel footage adds a new clue: a man and woman accept winnings from a lottery, and the boys recognize the man as Knobby, the truck driver who helped steal the truck. Based on information supplied by Charlie Manning, who is Manning’s nephew, the boys suspect Knobby is connected to Manning. Armed with this thread, they escape the reform school and head to the apartment of Dorothy Melton Dorothy Melton, the woman seen on the newsreel. The youths confront Dorothy and the surrounding couple, who had hoped to slip away out of town with the lottery money that actually belongs to Manning, who fears being exposed.
When Manning arrives at Dorothy’s apartment to demand his cut, he strikes Dorothy in a moment of double-crossing trouble. The police arrive just in time to arrest the criminals, and Bill receives a reprieve from the governor. As Anne and the boys send him off to report for active military duty, the story closes with a sense of vindication. In a final turn, Jed Miller faces the possibility of duty as well, while Bill, now facing the prospect of reformatory discipline, signals his intention to stand up, inviting the moment for a showdown as he warns the sergeant to book him up for the guard house before the film ends with a rousing cheer from the boys.
