In the slums, teenager Frankie Warren hangs out with a rowdy gang who one day knock him out in a fight. In court, the boys refuse to reveal who struck the knockout blow, and all are subsequently sentenced to a reformatory, cruelly run by two corrupt guards. New deputy commissioner Mark Braden arrives determined to change things, but despite the help of Frankie’s sister, Mark’s reform plans — and Frankie’s future — may be sabotaged from within.